Journal of Food Bioactives, ISSN 2637-8752 print, 2637-8779 online
Journal website www.isnff-jfb.com

Review

Volume 1, March 2018, pages 56-92

Bioactive components and health effects of pecan nuts and their by-products: a review

Figures

Figure 1.
Figure 1.

Pecan production in Mexico and United States from 1980 to 2016.

Figure 2.
Figure 2.

Chemical structures of common phytochemicals in pecan.

Tables

Table 1. Proximal composition and micronutrient content of the pecan nut (content in 100 g of nut)
 
NutrientUnitContent
Abbreviations: Kcal, Kilocalories; RAE, retinol activity equivalents; IU, international units. Adapted from USDA (2016).
Proximate composition
Waterg3.52
Energykcal691
Proteing9.17
Total lipid (fat)g71.97
Ashg1.49
Carbohydrate, by differenceg13.86
Fiber, total dietaryg9.6
Sugars, totalg3.97
Sucroseg3.9
Glucose (dextrose)g0.04
Fructoseg0.04
Starchg0.46
Minerals
Calcium, Camg70
Iron, Femg2.53
Magnesium, Mgmg121
Phosphorus, Pmg277
Potassium, Kmg410
Sodium, Namg0
Zinc, Znmg4.53
Copper, Cumg1.2
Manganese, Mnmg4.5
Selenium, Seµg3.8
Fluoride, Fµg10
Vitamins
Vitamin C, total ascorbic acidmg1.1
Thiaminmg0.66
Riboflavinmg0.13
Niacinmg1.167
Pantothenic acidmg0.863
Vitamin B-6mg0.21
Folate, totalµg22
Choline, totalmg40.5
Betainemg0.7
Vitamin A, RAEµg3
Vitamin A, IUIU56
Vitamin E (alpha-tocopherol)mg1.4
Vitamin K (phylloquinone)µg3.5

 

Table 2. Bioactive components of pecan oil
 
CompoundContentExtractionComments on the samplesReferences
Abbreviations: RT, room temperature; DsS, desmethylsterols; PL, phospholipid; PS, phosphatidylserine; PI, phosphatidylinositol; PC, phosphatidylcholine; PA, phosphatidic acid; PE, phosphatidylethanolamine; PG, phosphatidylglycerol; GAE, gallic acid equivalents; TocE, α-tocopherol equivalents.
Monounsaturated fatty acids (MUFA)
Oleic acid (w-9)56.3–72.5 %Supercritical fluidsDifferent cultivars and extraction conditions, residual oilAlexander et al., 1997; Salvador et al., 2016
51.1–75.3 %Soxhlet with different solventsDifferent cultivars, locations, harvest years, tree ages, ripening stages, residual oil, raw and roasted nutsBouali et al., 2013; Juhaimi et al., 2017; Salvador et al., 2016; Toro-Vazquez et al., 1999; Venkatachalam et al., 2007; Venkatachalam & Sathe, 2006; Wakeling et al., 2001
38.2–75.0 %RT with different solvents and extraction protocolsDifferent cultivars, locations, harvest years, extraction conditionsDerewiaka et al., 2014; Domínguez-Avila et al., 2013; Flores-Córdova et al., 2016; Miraliakbari & Shahidi, 2008b; Ryan et al., 2006; Villarreal-Lozoya et al., 2007
53.9–78.1 %Mechanical pressingDifferent cultivars, harvest years and extraction conditions, commercial oils from different locationsCastelo-Branco et al., 2016; do Prado et al., 2013; Fernandes et al., 2017; Gong et al., 2017; Scapinello et al., 2017
53.0–65.3 %Pressurized n-butaneDifferent extraction conditionsScapinello et al., 2017
Polyunsaturated fatty acids (PUFA)
Linoleic acid (w-6)17.3–33.4 %Supercritical fluidsDifferent cultivars and extraction conditions, residual oilAlexander et al., 1997; Salvador et al., 2016
16.2–37.5 %Soxhlet with different solventsDifferent cultivars, locations, harvest years, tree ages, ripening stages, residual oil, raw and roasted nutsBouali et al., 2013; Juhaimi et al., 2017; Salvador et al., 2016; Toro-Vazquez et al., 1999; Venkatachalam et al., 2007; Venkatachalam & Sathe, 2006; Wakeling et al., 2001
15.0–50.3 %RT with different solvents and extraction protocolsDifferent cultivars, locations, harvest years, extraction conditionsDerewiaka et al., 2014; Domínguez-Avila et al., 2013; Flores-Córdova et al., 2016; Miraliakbari & Shahidi, 2008b; Ryan et al., 2006; Villarreal-Lozoya et al., 2007
13.6–32.9 %Mechanical pressingDifferent cultivars, harvest years and extraction conditions, commercial oils from different locationsCastelo-Branco et al., 2016; do Prado et al., 2013; Fernandes et al., 2017; Gong et al., 2017; Scapinello et al., 2017
24.8–26.2 %Pressurized n-butaneDifferent extraction conditionsScapinello et al. 2017
Linolenic acid (w-3)ND–4.9 %Supercritical fluidsDifferent cultivars and extraction conditions, residual oilAlexander et al., 1997; Salvador et al., 2016
0.2–3.0 %Soxhlet with different solventsDifferent cultivars, locations, harvest years, tree ages, ripening stages, residual oil, raw and roasted nutsBouali et al., 2013; Juhaimi et al., 2017; Salvador et al., 2016; Toro-Vazquez et al., 1999; Venkatachalam et al., 2007; Venkatachalam & Sathe, 2006; Wakeling et al., 2001
0.7–5.0 %RT with different solvents and extraction protocolsDifferent cultivars, locations, harvest years, extraction conditionsDerewiaka et al., 2014; Domínguez-Avila et al., 2013; Miraliakbari & Shahidi, 2008b; Ryan et al., 2006; Villarreal-Lozoya et al., 2007
0.7–1.5 %Mechanical pressingDifferent cultivars, harvest years and extraction conditions, commercial oils from different locationsCastelo-Branco et al., 2016; do Prado et al., 2013; Fernandes et al., 2017; Gong et al., 2017; Scapinello et al., 2017
1.0–1.1 %Pressurized n-butaneDifferent extraction conditionsScapinello et al. 2017
Tocopherols
αND–122.4 mg/Kg oilSoxhlet oil extraction, direct injection in HPLCDifferent cultivars, locations, tree ages, ripening stages, raw and roasted nutsBouali et al., 2013; Juhaimi et al., 2017; Kornsteiner et al., 2006; Toro-Vazquez et al., 1999
1.4–363.2 mg/Kg oilMechanical pressing of oil, direct injection in HPLCDifferent cultivars and harvest years, commercial oils from different locationsCastelo-Branco et al., 2016; do Prado et al., 2013; Fernandes et al., 2017; Gong et al., 2017
5.9–18.2 mg/Kg oilRT oil extraction with different solvents, saponification before HPLCDifferent locations and extraction conditionsDerewiaka et al., 2014; Miraliakbari & Shahidi, 2008b; Miraliakbari & Shahidi, 2008c
0.6–1.9 mg/100 g nutRT or Soxhlet oil extraction, direct injection in HPLCDifferent cultivars and yearsChun et al., 2002; Robbins et al., 2015; Robbins et al., 2011; USDA, 2016
0.4–1.3 mg/100g nutCold saponification of ground nutsDifferent cultivarsPerez-Fernandez et al., 2017
γ21.0– 4,650 mg/Kg oilSoxhlet oil extraction, direct injection in HPLCDifferent cultivars, locations, tree ages, ripening stages, raw and roasted nutsBouali et al., 2013; Juhaimi et al., 2017; Kornsteiner et al., 2006; Toro-Vazquez et al., 1999
197.1–381.0 mg/Kg oilMechanical pressing of oil, direct injection in HPLCDifferent cultivars and harvest years, commercial oils from different locationsCastelo-Branco et al., 2016; do Prado et al., 2013; Fernandes et al., 2017; Gong et al., 2017
70.8–472.9 mg/Kg oilRT oil extraction with different solvents, saponification before HPLCDifferent locations and extraction conditionsDerewiaka et al., 2014; Miraliakbari & Shahidi, 2008b; Miraliakbari & Shahidi, 2008c
72.0–135.0 mg/Kg oilRT oil extraction, liquid/liquid extraction of tocopherolsDifferent cultivars, locations and yearsDomínguez-Avila et al., 2013; Villarreal-Lozoya et al., 2007
16.0–30.5 mg/100 g nutRT or Soxhlet oil extraction, direct injection in HPLCDifferent cultivars and yearsChun et al., 2002; Robbins et al., 2015; Robbins et al., 2011; USDA, 2016
8.7–31.1 mg/100g nutCold saponification of ground nutsDifferent cultivarsPerez-Fernandez et al., 2017
δND–112.2 mg/Kg oilSoxhlet oil extraction, direct injection in HPLCDifferent cultivars, locations, tree ages, ripening stages, raw and roasted nutsBouali et al., 2013; Juhaimi et al., 2017; Kornsteiner et al., 2006; Toro-Vazquez et al., 1999
0.07–2.4 mg/Kg oilMechanical pressing of oil, direct injection in HPLCDifferent cultivars and harvest years, commercial oils from different locationsCastelo-Branco et al., 2016; Fernandes et al., 2017; Gong et al., 2017
ND–6.2 mg/Kg oilRT oil extraction followed by saponification or liquid/liquid extractionDifferent locations, years, and extraction conditionsDomínguez-Avila et al., 2013; Miraliakbari & Shahidi, 2008b; Miraliakbari & Shahidi, 2008c
0.02–0.6 mg/100 g nutRT or Soxhlet oil extraction, direct injection in HPLCDifferent cultivars and yearsChun et al., 2002; Robbins et al., 2015; Robbins et al., 2011; USDA, 2016
ND–0.8 mg/100g nutCold saponification of ground nutsDifferent cultivarsPérez-Fernández et al., 2017
Tocotrienols
βND–0.009 mg/100g nutCold saponification of ground nutsDifferent cultivarsPérez-Fernández et al., 2017
γ<0.001–0.025 mg/100g nutCold saponification of ground nutsDifferent cultivarsPérez-Fernández et al., 2017
Phytosterols
Δ5-Avenasterol10.0–214.4 mg/100g oilSolvent extraction (RT or soxhlet)Different locations, extraction conditions and ripening stagesBouali et al., 2014; Derewiaka et al., 2014; Miraliakbari & Shahidi, 2008b
10.6–23.4 mg/100g oilMechanical pressingCommercial oils from raw and roasted pecanGong et al., 2017
15–16% total DsSMechanical pressingCommercial nuts and oilsFernandes et al., 2017
12.6–14.6 mg/100g nutSolvent extractionCommercial nutsPhillips et al., 2005; Robbins et al., 2011; USDA, 2016
Campesterol1.5–193.5 mg/100g oilSolvent extraction (RT or soxhlet)Different locations, years extraction conditions and ripening stagesBouali et al., 2014; Derewiaka et al., 2014; Domínguez-Avila et al., 2013; Miraliakbari & Shahidi, 2008b
5.7–67.1 mg/100g oilMechanical pressingCommercial oils from raw and roasted pecanGong et al., 2017
4.2–4.5% total DsSMechanical pressingCommercial nuts and oilsFernandes et al., 2017
5.9–6.0 mg/100g nutSolvent extractionCommercial nutsPhillips et al., 2005; Robbins et al., 2011; USDA, 2016
β-Sitosterol32.6–2,134 mg/100g oilSolvent extraction (RT or soxhlet)Different locations, years extraction conditions and ripening stagesBouali et al., 2014; Derewiaka et al., 2014; Domínguez-Avila et al., 2013; Miraliakbari & Shahidi, 2008b
91.4–234.3 mg/100g oilMechanical pressingCommercial oils from raw and roasted pecanGong et al., 2017
75–76% total DsSMechanical pressingCommercial nuts and oilsFernandes et al., 2017
116.5–130.1 mg/100g nutSolvent extractionCommercial nutsPhillips et al., 2005; Robbins et al., 2011; USDA, 2016
Stigmasterol0.3–100 mg/100g oilSolvent extraction (RT or soxhlet)Different locations, years extraction conditions and ripening stagesBouali et al., 2014; Derewiaka et al., 2014; Domínguez-Avila et al., 2013; Miraliakbari & Shahidi, 2008b
3.4–22.9 mg/100g oilMechanical pressingCommercial oils from raw and roasted pecanGong et al., 2017
0.9% total DsSMechanical pressingCommercial nuts and oilsFernandes et al., 2017
2.4–2.6 mg/100g nutSolvent extractionCommercial nutsPhillips et al., 2005; Robbins et al., 2011; USDA, 2016
Phospholipids (PL)
Total PL1.19 % total oilFolch oil extractionCommercial sampleSong et al., 2018
PS0.15–0.47 % total oilRT oil extractionDifferent extraction conditionsMiraliakbari & Shahidi, 2008a; Miraliakbari & Shahidi, 2008b
NDFolch oil extractionCommercial sampleSong et al., 2018
PI0.04–0.18 % total oilRT oil extractionDifferent extraction conditionsMiraliakbari & Shahidi, 2008a; Miraliakbari & Shahidi, 2008b
24.5 % total PLFolch oil extractionCommercial sampleSong et al., 2018
PC0.10–0.52 % total oilRT oil extractionDifferent extraction conditionsMiraliakbari & Shahidi, 2008a; Miraliakbari & Shahidi, 2008b
18.1 % total PLFolch oil extractionCommercial sampleSong et al., 2018
PANDRT oil extractionDifferent extraction conditionsMiraliakbari & Shahidi, 2008a; Miraliakbari & Shahidi, 2008b
24.6 % total PLFolch oil extractionCommercial sampleSong et al., 2018
PE17.1 % total PLFolch oil extractionCommercial sampleSong et al., 2018
PG10.3 % total PLFolch oil extractionCommercial sampleSong et al., 2018
Total sphingolipids
0.21–0.55 % total oilRT oil extractionDifferent extraction conditionsMiraliakbari & Shahidi, 2008a; Miraliakbari & Shahidi, 2008b
NDFolch oil extractionCommercial sampleSong et al., 2018
Total polyphenols
113–783 mgGAE/Kg oilSolvent extraction, liquid/liquid extraction of polyphenolsDifferent extraction conditions, locations and yearsDomínguez-Avila et al., 2013; Miraliakbari & Shahidi, 2008a
54–711 mgTocE/Kg oilSolvent extraction, liquid/liquid extraction of polyphenolsDifferent extraction conditions, locations and yearsMiraliakbari & Shahidi, 2008a
40 mg GAE/Kg oilCold pressing, liquid/liquid extraction of polyphenolsCommercial oilCastelo-Branco et al., 2016

 

Table 3. Total polyphenols, flavonoids and proanthocyanidins in pecan kernels and byproducts
 
Plant partContent in 100 g of sampleExtraction solventComments on the samplesReference
Abreviations/GAE, gallic acid equivalents; CAE, chlorogenic acid equivalents; EAE, ellagic acid equivalents; CE, catechin equivalents; QE, quercetin equivalents; PBE, procyanidin B2 equivalents. Notes/ 1reported in 100 g of deffated kernel; 2quantified by HPLC; 3quantified by the DMAC assay.
Total polyphenols (Folin-Ciocalteu assay)
Kernel2,016 mg GAEacetone/water/acetic acid (70/29.5/0.5)Commercial sampleWu et al., 2004
Kernel1,022–1,444 mg GAE75% acetone with Na2S2O5Commercial samplesKornsteiner et al., 2006
Kernel6,200–10,600 mg CAE170% acetoneDifferent cultivarsVillarreal-Lozoya et al., 2007
Kernel8,200–10,400 mg CAE170% acetoneDifferent cultivars and postharvest treatmentsVillarreal-Lozoya et al., 2009
Kernel1,227.3 mg GAE80% acetoneCommercial sample, free phenolicsYang et al., 2009
Kernel236.6 mg GAEMethanol/ethyl acetate after basic hydrolysisCommercial sample, bound phenolicsYang et al., 2009
Kernel1,170–1,250 mg GAE80% acetoneDifferent locationsde la Rosa et al., 2011
Kernel829–959 mg GAE80% acetoneDifferent locationsde la Rosa et al., 2014
Kernel1.82–2.62 mg EAEacetone/water/acetic acid (70/29.5/0.5)Different cultivarsRobbins et al., 2015
Kernel1,925–2,313 mg GAEmethanol/chloroform/1% NaCl (1/1/0.5)Different cultivarsFlores-Cordova et al., 2017
Nutshell29-63 g CAE70% acetoneDifferent cultivarsVillarreal-Lozoya et al., 2007
Nutshell11.7–16.7 g GAEwaterDifferent batchesdo Prado et al., 2009
Nutshell19.1 g GAEno informationno informationMedina et al., 2010
Nutshell6.5–9.2 g GAE80% acetoneDifferent locationsde la Rosa et al., 2011
Nutshell19.2 g GAEwaterno informationReckziegel et al., 2011
Nutshell9.4–18.1 g GAEwaterDifferent years and cultivarsdo Prado et al., 2013
Nutshell19.2 g GAEwaterCommercial sampleMüller et al., 2013
Nutshell12.8 g GAEwaterBarton varietyPorto et al., 2013
Nutshell2.4–5.4 g GAE80% acetoneDifferent locationsde la Rosa et al., 2014
Nutshell0.03–59.1 g GAEwater, ethanol, supercritical CO2Different extraction conditionsdo Prado et al., 2014
Nutshell1.4–25 mg GAEethanolDifferent cultivarsHawary et al., 2016
Nutshell42.6 g GAEwaterBarton varietyHilbig et al., 2016
Nutshell14.5–17.0 g GAEmethanol/chloroform/1% NaCl (1/1/0.5)Different cultivarsFlores-Cordova et al., 2017
Leave3.2–98 mg GAEethanolDifferent cultivarsHawary et al., 2016
Kernel cake690 mg GAE80% ethanolIndustrial byproductsSarkis et al., 2014
Kernel cake2.2–7.1 mg GAEethanol, acetone, supercritical CO2Different extraction conditionsSalvador et al., 2016
Total flavonoids (AlCl3 assay)
Kernel639.3 mg CE80% acetoneCommercial sample, free phenolicsYang et al., 2009
Kernel65.4 mg CEMethanol/ethyl acetate after basic hydrolysisCommercial sample, bound phenolicsYang et al., 2009
Kernel580–640 mg CE80% acetoneDifferent locationsde la Rosa et al., 2011
Kernel345–397 mg CE80% acetoneDifferent locationsde la Rosa et al., 2014
Nutshell2.6–3.6 g CE80% acetoneDifferent locationsde la Rosa et al., 2011
Nutshell1.6 g CEwaterBarton varietyPorto et al., 2013
Nutshell1.6–3.2 g CE80% acetoneDifferent locationsde la Rosa et al., 2014
Nutshell1.2–6.7 mg QEethanolDifferent cultivarsHawary et al., 2016
Nutshell9–30 mg 2methanolDifferent cultivarsHawary et al., 2016
Leave13–21 mg QEethanolDifferent cultivarsHawary et al., 2016
Leave107–173 mg 2methanolDifferent cultivarsHawary et al., 2016
Kernel cake690 mg CE80% ethanolIndustrial byproductsSarkis et al., 2014
Total proanthocyanidins (Vanillin-HCl assay)
Kernel2,300–4,700 mg CE170% acetoneDifferent cultivarsVillarreal-Lozoya et al., 2007
Kernel2,300–5,300 mg CE170% acetoneDifferent cultivars and postharvest treatmentsVillarreal-Lozoya et al., 2009
Kernel2,030–2,670 mg CE80% acetoneDifferent locationsde la Rosa et al., 2011
Kernel2,828–3,950 mg CE80% acetoneDifferent locationsde la Rosa et al., 2014
Kernel420–655 mg PBE3acetone/water/acetic acid (70/29.5/0.5)Different cultivarsRobbins et al., 2015
Kernel2,181–2,322 mg CEmethanol/chloroform/1% NaCl (1/1/0.5)Different cultivarsFlores-Cordova et al., 2017
Nutshell38.8–87.6 g CE70% acetoneDifferent cultivarsVillarreal-Lozoya et al., 2007
Nutshell2.6–4.8 g CEwaterDifferent cultivarsVillarreal-Lozoya et al., 2007
Nutshell3.5–4.8 g CEwaterDifferent batchesdo Prado et al., 2009
Nutshell14.46 g CEno informationno informationMedina et al., 2010
Nutshell31.6–46.4 g CE80% acetoneDifferent locationsde la Rosa et al., 2011
Nutshell3.6–4.9 g CEwaterDifferent years and cultivarsdo Prado, 2013
Nutshell5.8 g CEwaterno informationReckziegel et al., 2011
Nutshell5.8 g CEwaterCommercial sampleMüller et al., 2013
Nutshell4.7 g CEwaterBarton varietyPorto et al., 2013
Nutshell28.2–70.0 g CE80% acetoneDifferent locationsde la Rosa et al., 2014
Nutshell0.05–41.2 g CEwater, ethanol, supercritical CO2Different extraction conditionsdo Prado et al., 2014
Nutshell43.2–52.8 g CEmethanol/chloroform/1% NaCl (1/1/0.5)Different cultivarsFlores-Cordova et al., 2017
Kernel cake16.5–17.5 mg CE80% ethanolIndustrial byproductsSarkis et al., 2014
Kernel cake1.5–31.5 mg CEethanol, acetoneDifferent extraction conditionsSalvador et al., 2016
Total phenolic acids (HPLC)
Nutshell130–5,150 mgmethanolDifferent cultivarsHawary et al., 2016
Leave264–604 mgmethanolDifferent cultivarsHawary et al., 2016

 

Table 4. Individual phenolic compounds in pecan kernel
 
Phenolic group or familyIdentified compoundContentExtraction solventAnalytical techniqueReference
Abreviations/ HPLC-MS, high performance liquid chromatography-mass spectrometry; HPLC-DAD, high performance liquid chromatography-diode array detector; NP-HPLC, normal phase high performance liquid chromatography. Notes/ 1expressed per gram of deffated kernel; 2expressed per gram of whole kernel; 3expressed per gram of crude extract; 4expressed per 100 grams of whole kernel; 5quantified as ellagic acid + ellagic acid derivatives per gram of extract fraction; 6quantified as catechin + (epi)catechin derivatives per gram of extract fraction; 7solvent ratio 70/29.5/0.5 v/v.
Phenolic acids
Hydroxybenzoic acids and derivativesp-Hidroxybenzoic acid10.0–14.8 μg 1Acidified methanolGas chromatographySenter et al., 1980
29.0–90.1 μg 280% acetoneAcid hydrolysis, HPLC-MSde la Rosa et al., 2011
IDacetone/water/acetic acid7LH-20 fractionation, HPLC-MSRobbins et al., 2014
28.64–49.16 μg 3acetone/water/acetic acid7Acid or basic hydrolysis, HPLC-MSRobbins et al., 2015
3.0 μg 3acetone/water/acetic acid7LH-20 fractionation, HPLC-MSGong & Pegg, 2017
Gentisic acid1.2–7.7 μg 1Acidified metanolGas chromatographySenter et al., 1980
Protocatechuic acid4.0–7.2 μg 1Acidified metanolGas chromatographySenter et al., 1980
13.1–30.5 μg 280% acetoneAcid hydrolysis, HPLC-MSde la Rosa et al., 2011
20.99–24.08 μg 3acetone/water/acetic acid7Basic hydrolysis, HPLC-MSRobbins et al., 2015
14.46–32.71 mg460% metanolHPLC-DADJuhaimi et al., 2017
Protocatechuic acid hexosideIDacetone/water/acetic acid7LH-20 fractionation, HPLC-MSRobbins et al., 2014
3.3 μg 3acetone/water/acetic acid7LH-20 fractionation, HPLC-MSGong & Pegg, 2017
Vanillic acid3.1–6.0 μg 1Acidified metanolGas chromatographySenter et al., 1980
Gallic acid63.2–132.8 μg 1Acidified metanolGas chromatographySenter et al., 1980
651–∼2,000 μg 170 % acetoneBasic and acid hydrolysis, HPLC-DADVillarreal-Lozoya et al., 2007; Villarreal-Lozoya et al., 2009
64.3–274.5 μg 280% acetoneHPLC-MS, with or without hydrolysisde la Rosa et al., 2011
1,800 μg 280% acetoneAcid hydrolysis, HPLC-DADde la Rosa et al., 2014
IDacetone/water/acetic acid7LH-20 fractionation, HPLC-MSRobbins et al., 2014
7.6 μg 3acetone/water/acetic acid7LH-20 fractionation, HPLC-MSGong & Pegg, 2017
11.8–33.9 mg460% metanolHPLC-DADJuhaimi et al., 2017
Syringic acidIDAcidified metanolGas chromatographySenter et al., 1980
6.58–10.76 mg460% metanolHPLC-DADJuhaimi et al., 2017
Gallic acid derivativesMonogalloyl hexosideID80% acetoneHPLC-MSde la Rosa et al., 2011
IDacetone/water/acetic acid7LH-20 fractionation, HPLC-MSRobbins et al., 2014
4.6–10.4 μg 3acetone/water/acetic acid7LH-20 fractionation, HPLC-MSGong & Pegg, 2017
Digalloyl hexoside0.3 μg 3acetone/water/acetic acid7LH-20 fractionation, HPLC-MSGong & Pegg, 2017
Ethyl gallateIDacetone/water/acetic acid7LH-20 fractionation, HPLC-MSRobbins et al., 2014
1.5 μg 3acetone/water/acetic acid7LH-20 fractionation, HPLC-MSGong & Pegg, 2017
Ellagic acid and derivativesEllagic acid900–4,732 μg 170 % acetoneBasic and acid hydrolysis, HPLC-DADVillarreal-Lozoya et al., 2007; Villarreal-Lozoya et al., 2009
1,400–5,500 μg 280% acetoneHPLC-MS, with or without hydrolysisde la Rosa et al., 2011
3,600 μg 280% acetoneAcid hydrolysis, HPLC-DADde la Rosa et al., 2014
4.91–41.3 mg 5acetone/water/acetic acid7LH-20 fractionation, HPLC-MSRobbins et al., 2014
32.1–132.0 μg 3acetone/water/acetic acid7HPLC-MS, with or without hydrolysisRobbins et al., 2015
86.4 μg 3acetone/water/acetic acid7LH-20 fractionation, HPLC-MSGong & Pegg, 2017
Ellagic acid pentosidesID80% acetoneHPLC/MSde la Rosa et al., 2011
IDacetone/water/acetic acid7LH-20 fractionation, HPLC-MSRobbins et al., 2014
5.86–9.30 μg 3acetone/water/acetic acid7HPLC-MS, with or without hydrolysisRobbins et al., 2015
8.3 μg 3acetone/water/acetic acid7LH-20 fractionation, HPLC-MSGong & Pegg, 2017
Ellagic acid hexosidesIDacetone/water/acetic acid7LH-20 fractionation, HPLC-MSRobbins et al., 2014
2.9 μg 3acetone/water/acetic acid7LH-20 fractionation, HPLC-MSGong & Pegg, 2017
Methyl and dimethyl ellagic acid isomersID80% acetoneAcid hydrolysis, HPLC-MSde la Rosa et al., 2011
IDacetone/water/acetic acid7LH-20 fractionation, HPLC-MSRobbins et al., 2014
3.09–7.35 μg 3acetone/water/acetic acid7HPLC-MS, with or without hydrolysisRobbins et al., 2015
4.8 μg 3acetone/water/acetic acid7LH-20 fractionation, HPLC-MSGong & Pegg, 2017
Methylated ellagic acid glycosidesIDacetone/water/acetic acid7LH-20 fractionation, HPLC-MSRobbins et al., 2014
0.8–17.7 μg 3acetone/water/acetic acid7LH-20 fractionation, HPLC-MSGong & Pegg, 2017
Galloylated ellagic acid derivativesIDacetone/water/acetic acid7LH-20 fractionation, HPLC-MSRobbins et al., 2014
5.81–8.46 μg 3acetone/water/acetic acid7HPLC-MS, with or without hydrolysisRobbins et al., 2015
2.1 μg 3acetone/water/acetic acid7LH-20 fractionation, HPLC-MSGong & Pegg, 2017
Galloyl ellagic acid pentosidesIDacetone/water/acetic acid7LH-20 fractionation, HPLC-MSRobbins et al., 2014
4.18–6.23 μg 3acetone/water/acetic acid7HPLC-MS, with or without hydrolysisRobbins et al., 2015
8.3–12.0 μg 3acetone/water/acetic acid7LH-20 fractionation, HPLC-MSGong & Pegg, 2017
HHDP-hexosidesIDacetone/water/acetic acid7LH-20 fractionation, HPLC-MSRobbins et al., 2014
2.4–7.0 μg 3acetone/water/acetic acid7LH-20 fractionation, HPLC-MSGong & Pegg, 2017
Galloylated-HHDP-hexosides0.3–9.6 μg 3acetone/water/acetic acid7LH-20 fractionation, HPLC-MSGong & Pegg, 2017
Valoneic acid dilactoneID80% acetoneAcid hydrolysis, HPLC-MSde la Rosa et al., 2011
IDacetone/water/acetic acid7LH-20 fractionation, HPLC-MSRobbins et al., 2014
7.71–262.4 μg 3acetone/water/acetic acid7HPLC-MS, with or without hydrolysisRobbins et al., 2015
48.2 μg 3acetone/water/acetic acid7LH-20 fractionation, HPLC-MSGong & Pegg, 2017
Hydroxy cinnamic acids and derivativesp-Coumaric acid0.73–1.26 mg 460% methanolHPLC-DADJuhaimi et al., 2017
Caffeic acid2.1 μg 3acetone/water/acetic acid7LH-20 fractionation, HPLC-MSGong & Pegg, 2017
6.27–8.48 mg 460% metanolHPLC-DADJuhaimi et al., 2017
Caffeic acid hexosideIDacetone/water/acetic acid7LH-20 fractionation, HPLC-MSRobbins et al., 2014
4.19–6.74 μg 3acetone/water/acetic acid7HPLC-MS, with or without hydrolysisRobbins et al., 2015
Ferulic acid4.50–11.54 mg 460% methanolHPLC-DADJuhaimi et al., 2017
Sinapoylquinic acid11.71–14.71 μg 3acetone/water/acetic acid7Basic hydrolysis, HPLC-MSRobbins et al., 2015
Other non-flavonoids
1,2-dihydroxy benzene13.38–28.77 mg460% metanolHPLC-DADJuhaimi et al., 2017
Resveratrol1.21–3.11 mg 460% metanolHPLC-DADJuhaimi et al., 2017
Flavonoids
Monomeric flavan-3-olsCatechin7.2 mg 4Acidified methanolAcid hydrolysis, HPLC-DADHarnly et al., 2006; USDA, 2016
ID70 % acetoneBasic and acid hydrolysis, HPLC-DADVillarreal-Lozoya et al., 2007; Villarreal-Lozoya et al., 2009
ID80% acetoneHPLC-MSde la Rosa et al., 2011
2.5 mg 470% acetoneHPLC/MS/MSBittner et al., 2013
500 μg 280% acetoneLH-20 fractionation, HPLC-DADde la Rosa et al., 2014
16.5–35.5 mg 6acetone/water/acetic acid7LH-20 fractionation, HPLC-MSRobbins et al., 2014
10.6–82.3 μg 3acetone/water/acetic acid7HPLC-MS, with or without hydrolysisRobbins et al., 2015
9.9 μg 3acetone/water/acetic acid7LH-20 fractionation, HPLC-DADGong & Pegg, 2017
18.3–47.6 mg460% methanolHPLC-DADJuhaimi et al., 2017
(Epi)catechin hexosideIDacetone/water/acetic acid7LH-20 fractionation, HPLC-DADRobbins et al., 2014
10.7 μg 3acetone/water/acetic acid7LH-20 fractionation, HPLC-DADGong & Pegg, 2017
Epicatechin0.8 mg 4Acidified methanolAcid hydrolysis, HPLC-DADHarnly et al., 2006; USDA, 2016
ID70% acetoneBasic and acid hydrolysis, HPLC-DADVillarreal-Lozoya et al., 2007
600 μg 280% acetoneLH-20 fractionation, HPLC-DADde la Rosa et al., 2014
2.8 μg 3acetone/water/acetic acid7LH-20 fractionation, HPLC-MSGong & Pegg, 2017
Epigallocatechin5.6 mg 4Acidified metanolAcid hydrolysis, HPLC-DADHarnly et al., 2006; USDA, 2016
ID (as (epi) gallocatechin)80% acetoneAcid hydrolysis, HPLC-MSde la Rosa et al., 2011
ID (as (epi) gallocatechin)acetone/water/acetic acid7LH-20 fractionation, HPLC-MSRobbins et al., 2014
(Epi)catechin-3-gallateIDacetone/water/acetic acid7LH-20 fractionation, HPLC-MSRobbins et al., 2014
2.0–4.2 μg 3acetone/water/acetic acid7LH-20 fractionation, HPLC-MSGong & Pegg, 2017
Epigallocatechin-3-gallate2.3 mg 4Acidified methanolAcid hydrolysis, HPLC-DADHarnly et al., 2006; USDA, 2016
ID (as (epi) gallocatechin-3-gallate)acetone/water/acetic acid7LH-20 fractionation, HPLC-MSRobbins et al., 2014
Oligo and polymeric flavan-3-olsDimers42.1 mg 4acetone/water/acetic acid7LH-20 fractionation, NP-HPLC-MSGu et al., 2004; USDA, 2016
B-type procyanidin dimersIDacetone/water/acetic acid7LH-20 fractionation, HPLC-MSRobbins et al., 2014
3.93–6.03 μg 3acetone/water/acetic acid7HPLC/MSRobbins et al., 2015
1.3–31.42 μg 3acetone/water/acetic acid7LH-20 fractionation, HPLC-MSGong & Pegg, 2017
Procyanidin B1 (B-type dimer)1.76 mg 470% acetoneHPLC/MS/MSBittner et al., 2013
ID80% acetoneLH-20 and Toyopearl fractionation, NP-HPLC-MSLerma-Herrera et al., 2017
Procyanidin B2 (B-type dimer)0.18 mg 470% acetoneHPLC/MS/MSBittner et al., 2013
ID80% acetoneLH-20 and Toyopearl fractionation, NP-HPLC-MSLerma-Herrera et al., 2017
Procyanidin B3 (B-type dimer)4.87 mg 470% acetoneHPLC/MS/MSBittner et al., 2013
Procyanidin B6 (B-type dimer)0.59 mg 470% acetoneHPLC/MS/MSBittner et al., 2013
Procyanidin B7 (B-type dimer)0.49 mg 470% acetoneHPLC/MS/MSBittner et al., 2013
A-type procyanidin dimersIDacetone/water/acetic acid7LH-20 fractionation, HPLC-MSRobbins et al., 2014
4.47–8.49 μg 3acetone/water/acetic acid7HPLC/MSRobbins et al., 2015
0.7–3.0 μg 3acetone/water/acetic acid7LH-20 fractionation, HPLC-MSGong & Pegg, 2017
ID80% acetoneLH-20 and Toyopearl fractionation, NP-HPLC-MSLerma-Herrera et al., 2017
Trimers26.0 mg 4acetone/water/acetic acid7LH-20 fractionation, NP-HPLC-MSGu et al., 2004; USDA, 2016
B-type procyanidin trimersIDacetone/water/acetic acid7LH-20 fractionation, NP-HPLC-MSRobbins et al., 2014
18.34 μg 3acetone/water/acetic acid7LH-20 fractionation, NP-HPLC-MSGong & Pegg, 2017
ID80% acetoneLH-20 and Toyopearl fractionation, NP-HPLC-MSLerma-Herrera et al., 2017
Procyanidin C2 (B-type trimer)5.02 mg 470% acetoneHPLC/MS/MSBittner et al., 2013
B-type prodelphinidin trimersIDacetone/water/acetic acid7LH-20 fractionation, NP-HPLC-MSRobbins et al., 2014
ID80% acetoneLH-20 and Toyopearl fractionation, NP-HPLC-MSLerma-Herrera et al., 2017
B-type procyanidin tetramersIDacetone/water/acetic acid7LH-20 fractionation, NP-HPLC-MSRobbins et al., 2014
7.08 μg 3acetone/water/acetic acid7LH-20 fractionation, NP-HPLC-MSGong & Pegg, 2017
ID80% acetoneLH-20 and Toyopearl fractionation, NP-HPLC-MSLerma-Herrera et al., 2017
B-type prodelphinidin tetramersIDacetone/water/acetic acid7LH-20 fractionation, NP-HPLC-MSRobbins et al., 2014
B-type procyanidin pentamersIDacetone/water/acetic acid7LH-20 fractionation, NP-HPLC-MSRobbins et al., 2014
5.53 μg 3acetone/water/acetic acid7LH-20 fractionation, NP-HPLC-MSGong & Pegg, 2017
B-type prodelphinidin pentamersIDacetone/water/acetic acid7LH-20 fractionation, NP-HPLC-MSRobbins et al., 2014
B-type procyanidin hexamers1.62 μg 3acetone/water/acetic acid7LH-20 fractionation, NP-HPLC-MSGong & Pegg, 2017
B-type prodelphinidin hexamersIDacetone/water/acetic acid7LH-20 fractionation, NP-HPLC-MSRobbins et al., 2014
Tetramers-hexamers101.4 mg 4acetone/water/acetic acid7LH-20 fractionation, NP-HPLC-MSGu et al., 2004; USDA, 2016
B-type prodelphinidin heptamers0.41 μg 3acetone/water/acetic acid7LH-20 fractionation, NP-HPLC-MSGong & Pegg, 2017
Heptamers-decamers84.2 mg 4acetone/water/acetic acid7LH-20 fractionation, NP-HPLC-MSGu et al., 2004; USDA, 2016
Larger polymers223.0 mg 4acetone/water/acetic acid7LH-20 fractionation, NP-HPLC-MSGu et al., 2004; USDA, 2016
AnthocyanidinsCyanidin10.74 mg 4Acidified methanolAcid hydrolysis, HPLC-DADHarnly et al., 2006; USDA, 2016
Delphinidin7.3 mg 4Acidified methanolAcid hydrolysis, HPLC-DADHarnly et al., 2006; USDA, 2016
FlavonolsKaempferol2.68–5.21 mg 460% metanolHPLC-DADJuhaimi et al., 2017
Quercetin3.67–10.01 mg 460% metanolHPLC-DADJuhaimi et al., 2017
Isorhamnetin1.67–4.55 mg 460% metanolHPLC-DADJuhaimi et al., 2017
Rutin6.71–12.67 mg 460% metanolHPLC-DADJuhaimi et al., 2017

 

Table 5. Individual phenolic compounds in pecan by-products
 
Phenolic classGroupIdentified compoundContent (mg/g)Extraction solventAnalytical techniqueReference
Abreviations: ID, identified, not quantified; L-L, liquid-liquid; mDP, mean degree of polymerization, NP-HPLC, normal phase HPLC. Notes: 1values reported as μg/mL. 2mg/g of extract.
Compounds in bark
Phenolic acidsHydroxybenzoic acidsProtocatechuic acidID80% Ethanol; L-L extractionLH-20 fractionation, NMR analysisAbdalla et al., 2011
FlavonoidsFlavonolsQuercetinID80% Ethanol; L-L extractionLH-20 fractionation, NMR analysisAbdalla et al., 2011
AzaleatinID80% Ethanol; L-L extractionLH-20 fractionation, NMR analysisAbdalla et al., 2011
CaryatinID80% Ethanol; L-L extractionLH-20 fractionation, NMR analysisAbdalla et al., 2011
Caryatin-3′-methyl etherID80% Ethanol; L-L extractionLH-20 fractionation, NMR analysisAbdalla et al., 2011
Caryatin-3′-sulfateID80% Ethanol; L-L extractionLH-20 fractionation, NMR analysisAbdalla et al., 2011
Caryatin-3′-methyl ether-7-O-b-glucosideID80% Ethanol; L-L extractionLH-20 fractionation, NMR analysisAbdalla et al., 2011
Compounds in leaves
Phenolic acidsHydroxybenzoic acids and derivativesEllagic acidIDEthanolLH-20 fractionation, NMR analysisGad et al., 2007
Ellagic acid75.04WaterHPLC-DADBottari et al., 2017
Ellagic acid118.51EthanolHPLC-DADBottari et al., 2017
Ellagic acid1.8–0.59MethanolHPLC-DADHawary et al., 2016
Ellagic acid derivative45.61WaterHPLC-DADBottari et al., 2017
Ellagic acid derivative69.37EthanolHPLC-DADBottari et al., 2017
3,3′-Dimethoxy ellagic acidIDEthanolLH-20 fractionation, NMR analysisGad et al., 2007
Gallic acidIDEthanolLH-20 fractionation, NMR analysisGad et al., 2007
Gallic Acid68.15WaterHPLC-DADBottari et al., 2017
Gallic acid87.32EthanolHPLC-DADBottari et al., 2017
Gallic acid0.34–0.08MethanolHPLC-DADHawary et al., 2016
Methyl gallateIDEthanolLH-20 fractionation, NMR analysisGad et al., 2007
2,3-Digalloyl-β-D-4C1-glucopyranosideIDEthanolLH-20 fractionation, NMR analysisGad et al., 2007
p-Hydroxy benzoic acidIDEthanolLH-20 fractionation, NMR analysisGad et al., 2007
p-Hydroxy benzoic acid0.04–0.024MethanolHPLC-DADHawary et al., 2016
protocatechuic acid0.83–0.27MethanolHPLC-DADHawary et al., 2016
Pyrogallic acid1.6–0.45MethanolHPLC-DADHawary et al., 2016
Salicylic acid0.19–0.02MethanolHPLC-DADHawary et al., 2016
Syringic acid0.048–0.0MethanolHPLC-DADHawary et al., 2016
Hydroxycinnamic acidsCaffeic acid0.13–0.0MethanolHPLC-DADHawary et al., 2016
Other non-flavonoidsCatechol0.45–0.14MethanolHPLC-DADHawary et al., 2016
Cinnamic acid0.04–0.0MethanolHPLC-DADHawary et al., 2016
Ferulic acid0.13–0.02MethanolHPLC-DADHawary et al., 2016
FlavonoidsFlavonesApigenin0.02–0.0MethanolHPLC-DADHawary et al., 2016
Hesperidin0.20–0.0MethanolHPLC-DADHawary et al., 2016
Hesperetin0.21–0.02MethanolHPLC-DADHawary et al., 2016
FlavonolsKaempferol0.08–0.0MethanolHPLC-DADHawary et al., 2016
Kaempferol-3-O-(6′.-O-galloyl)-β-D-galactopyranosideIDEthanolLH-20 fractionation, NMR analysisGad et al., 2007
Kaempferol-3-O-α-D-galactopyranosideIDEthanolLH-20 fractionation, NMR analysisGad et al., 2007
Quercetin0.08–0.0MethanolHPLC-DADHawary et al., 2016
Quercitrin1.08–0.26MethanolHPLC-DADHawary et al., 2016
Quercetin-3-o-(6′.-o-galloyl)-β-D-galactopyranosideIDEthanolLH-20 fractionation, NMR analysisGad et al., 2007
Rutin3.84WaterHPLC-DADBottari et al., 2017
Rutin4.03EthanolHPLC-DADBottari et al., 2017
Rutin0.60–0.0methanolHPLC-DADHawary et al., 2016
TrifolinIDEthanolLH-20 fractionation, NMR analysisGad et al., 2007
FlavanonesNaringenin0.17-0.0methanolHPLC-DADHawary et al., 2016
Monomeric flavan-3-olsCatechin43.27WaterHPLC-DADBottari et al., 2017
Catechin40.19EthanolHPLC-DADBottari et al., 2017
Epigallocatechin17.34WaterHPLC-DADBottari et al., 2017
Epigallocatechin10.17EthanolHPLC-DADBottari et al., 2017
Epigallocatechin-3-O-gallateIDEthanolLH-20 fractionation, NMR analysisGad et al., 2007
Compounds in kernel cake (byproduct from the oil industry)
Phenolic acidsHydroxybenzoic acidsEllagic acidID80% ethanolAcid and basic hydrolysis, HPLC-DADSarkis et al., 2014
Gallic acidID80% ethanolAcid and basic hydrolysis, HPLC-DADSarkis et al., 2014
FlavonoidsMonomeric flavan-3-olsCatechinID80% ethanolAcid and basic hydrolysis, HPLC-DADSarkis et al., 2014
EpicatechinID80% ethanolAcid and basic hydrolysis, HPLC-DADSarkis et al., 2014
Compounds in nutshell
Phenolic acidsBenzoic acid0.18–0.0MethanolHPLC-DADHawary et al., 2016
Hydroxybenzoic acidsEllagic acid0.880% acetoneAcid hydrolysis, HPLC-DADde la Rosa et al., 2014
Ellagic acid37.141WaterHPLC-DADHilbig et al., 2018
Ellagic acid0.58WaterAcid hydrolysis, HPLC-DADPorto et al., 2013
Ellagic acidID70% ethanolHPLC UV detectorRuiz-Martínez et al., 2011
Ellagic acid0.14methanolHPLC-DADFlores-Córdova et al., 2017
Ellagic acid1.8WaterAcid hydrolysis, HPLC-DADPorto et al., 2013
Gallic Acid18WaterHPLC UV detectorBenvegnu et al., 2010
Gallic acid2.380% acetoneAcid hydrolysis, HPLC-DADde la Rosa et al., 2014
Gallic acid0.17–0.19methanolHPLC-DADFlores-Córdova et al., 2017
Gallic acid2.16–0.0methanolHPLC-DADHawary et al., 2016
Gallic Acid5.741WaterHPLC-DADHilbig et al., 2018
Gallic acid0.87WaterAcid hydrolysis, HPLC-DADPorto et al., 2013
Gallic acid124.3WaterHPLC UV detectordo Prado et al., 2014
Gallic acid828.7ethanolHPLC UV detectordo Prado et al., 2014
Gallic acid167.09WaterHPLC-DADTrevisan et al., 2014
Gallic acid2.69WaterAcid hydrolysis, HPLC-DADPorto et al., 2013
p-Hydroxy benzoic acid0.951WaterHPLC-DADHilbig et al., 2018
p-Hydroxy benzoic acid148.9EthanolHPLC UV detectordo Prado et al., 2014
Protocatechuic acid1.99–0.09MethanolHPLC-DADHawary et al., 2016
Pyrogallic acid42.88–0.0MethanolHPLC-DADHawary et al., 2016
Salicylic acid0.01–0.0MethanolHPLC-DADHawary et al., 2016
Vanillic acid1.36–0.30MethanolHPLC-DADHawary et al., 2016
Vanillic acid0.27–.0.1MethanolHPLC-DADHawary et al., 2016
Vanillic acid2.181WaterHPLC-DADHilbig et al., 2018
hydroxycinnamic acid derivatives2-Hydroxycinnamic acidID70% ethanolHPLC UV detectorRuiz-Martínez et al., 2011
Caffeic acid1.761WaterHPLC-DADHilbig et al., 2018
Chlorogenic acid2.01–0.0MethanolHPLC-DADHawary et al., 2016
Chlorogenic acid5.021WaterHPLC-DADHilbig et al., 2018
Chlorogenic acid233.42WaterHPLC UV detectordo Prado et al., 2014
Chlorogenic acid137.92EthanolHPLC UV detectordo Prado et al., 2014
Ferulic acid0.13–0.0MethanolHPLC-DADHawary et al., 2016
Other non-flavonoidsCatechol2.21–0.54MethanolHPLC-DADHawary et al., 2016
FlavonoidsFlavonesHesperetin0.07–0.0MethanolHPLC-DADHawary et al., 2016
FlavonolsKaempferol0.055–0.007MethanolHPLC-DADHawary et al., 2016
Quercetin0.05–0.0MethanolHPLC-DADHawary et al., 2016
Quercitrin0.02–0.0MethanolHPLC-DADHawary et al., 2016
QuercitrinID70% ethanolHPLC UV detectorRuiz-Martínez et al., 2011
Rutin13.84WaterHPLC-DADTrevisan et al., 2014
Rutin0.14–0.0MethanolHPLC-DADHawary et al., 2016
FlavanonesNaringenin0.08–0MethanolHPLC-DADHawary et al., 2016
Monomeric flavan-3-olsCatechin0.159–0.191methanolHPLC-DADFlores-Córdova et al., 2017
Catechin1.71WaterHPLC-DADHilbig et al., 2018
CatechinID70% ethanolHPLC UV detectorRuiz-Martínez et al., 2011
Catechin50.26WaterHPLC-DADTrevisan et al., 2014
CatechinID80% acetoneLH-20 fractionation, HPLC-MSVázquez-Flores et al., 2017
CatechinID80% acetoneLH 20 and Toyopearl fractionation, NP-HPLC-MSLerma-Herrera et al., 2017
Epicatechin5.611WaterHPLC-DADHilbig et al., 2018
Epicatechin gallate3.341WaterHPLC-DADHilbig et al., 2018
Epicatechin gallate0.342ethanolHPLC UV detectordo Prado et al., 2014
Epigallocatechin0.380% acetoneHPLC-DADde la Rosa et al., 2014
Epigallocatechin161.621WaterHPLC-DADHilbig et al., 2018
Epigallocatechin5184.32waterHPLC UV detectordo Prado et al., 2014
Epigallocatechin120.22ethanolHPLC UV detectordo Prado et al., 2014
EpigallocatechinID80% acetone,LH 20 fractionation, HPLC-MS (ion trap)Vázquez-Flores et al., 2017
Oligo and polymeric flavan-3-olsProcyanidins and prodelphinidis with mDP 3.4–12ID80% acetone,LH 20 fractionation, HPLC-MS (ion trap)Vázquez-Flores et al., 2017
Procyanidin B1 (B-type dimer)ID80% acetoneLH 20 and Toyopearl fractionation, NP-HPLC-MSLerma-Herrera et al., 2017
Procyanidin B2 (B-type dimer)ID80% acetoneLH 20 and Toyopearl fractionation, NP-HPLC-MSLerma-Herrera et al., 2017
B- type procyanidin trimers to hexamersID80% acetoneLH 20 and Toyopearl fractionation, NP-HPLC-MSLerma-Herrera et al., 2017
B-type prodelphinidin trimerID80% acetoneLH 20 and Toyopearl fractionation, NP-HPLC-MSLerma-Herrera et al., 2017

 

Table 6. Biological activity pecan kernel
 
Activitysamplemodelresultscommentsreference
LMW: Low molecular weight extract, HMW: High molecular weight extract, EC50: median effective dose, ↓: decrease compared to control, ↑: increase compared to control, ↔ no change compared to control, TC: total cholesterol, LDL: Low-density lipoprotein cholesterol, HDL: high-density lipoprotein cholesterol, non-HDL: non-high-density lipoprotein cholesterol, VLDL: very Low-density lipoprotein cholesterol, TAG: triacylglyceride, APOB: apolipoprotein B, APOA1: apolipoprotein A1, LDLR: LDL receptor, LXRa: LXRa, MDA: Malondialdehyde, TBARS: thiobarbituric acid-reactive substances, SOD: superoxide dismutase, ORAC: oxygen radical absorbance capacity, FRAP: ferric reducing ability, TEAC: Trolox equivalent antioxidant capacity, SFA: saturated fatty acids, MUFA: monounsaturated fatty acids, PUFA: polyunsaturated fatty acids, BMI: body mass index, HTB4: bladder carcinoma cell line, LLC-PK1:, non-carcinogenic kidney epithelial cell line, Caco-2: heterogeneous human epithelial colorectal adenocarcinoma cells, HepG2: liver hepatocellular carcinoma cells, CGNs: cerebellar granule neurons cells, ALS: amyotropic lateral sclerosis, PAC: proanthocyanidins, GFAP: glial fibrillary acidic protein.
anti-inflammatorycrude extract, HMW and LMW extractsLPS-stimulated inflammation in murine RAW 264.7 macrophage cell lines↓ NO production (LMW); ↓ ROS production (LMW); Slight cytotoxicity (at 25 and 50 μg/mL); ↔ NO and ROS production (crude extract and HMW)dose dependent. Effect may be due to the presence of PACRobbins et al., 2016
antiproliferative80% acetone extractHepG2 and Caco-2 cellsEC50: 9.7 mg/mL (HepG2); EC50 = 2.5 mg/mL (Caco-2)dose dependent, weak correlation with total phenols and flavonoids contentYang et al., 2009
antiproliferativekernel HMW fractionHTB4 bladder and LLC-PK1 cellsEC50: 0.26 mg/mL (HTB4 bladder); EC50: 0.55 mg/mL (LLC-PK1)de la Rosa et al., 2014
cancer preventionwhole pecanaberrant crypt foci (AFC) induced in male rats↓proximal and distal colon ACF; ↓crypt multiplicity; ↑ GST; ↑CAT; ↑SOD5 and 10% substitution diets, 17 weeksMiller et al., 2010
cell protective0.05% pecan dietTransgenic mice expressing G93A mutant human SOD-1↓ oxidative stress; Delay in ↓ motor neuron function; ↑ survival motor neurons; ↓ oligomerization of SOD-1; ↓ GFAP levels in lumbar spinal cordmodel used to study ALSSuchy et al., 2010
cell protectivepecan oilovariectomized Wistar female rat↔ serum estradiol; ↓ MDA; ↓ TBARS; ↑ SOD (similar to control); ↓ apoptosis of hippocampal cells; ↓ Caspase-3 activitydose dependentZhao et al., 2011
cell protectiveAcetone extractCGNs cellsEC50: 4.3 mg/mL; ↓ H2O2 cytotoxicityExtract concentration 10 times lower than EC50. Dose dependentde la Rosa et al., 2014
digestive enzymes inhibitionproanthocyanidinsin vitro digestive system↓ lipase (29.9%); ↓ amylase (45.9%); ↓ trypsin (40.2%)inhibition activity depended on enzyme typeVáquez-Flores et al., 2017
modulate lipid metabolismwhole pecan (WP); pecan oil (PO); Pecan phenolics (PP)high fat diets supplemented with WP, PO or PP Wistar rats for 63 days↓ Adiponectin (all treatments); ↓ TC, LDL, non-HDL (PP, WP); ↑ APOB, LDLR (WP); ↑LXRa (PP); ↓ MDA (TBARS) (WP); ↓ SOD (WP, PP)rats consumed less high fat diet compared to control. Final weight was similar for all treatmentsDomíguez-Avila et al., 2015
antioxidant, bioavailability of compoundsWhole pecan breakfastAcute evaluation (24 h) in 16 healthy volunteers. Isocaloric breakfast (90 g)↑ORAC values (hydrophilic and lipophilic, 2 h); ↑ serum γ-tocopherol (8 h); ↔ FRAP; ↔ TC; ↓ oxidized LDL (up to 8 h); ↓oxidized LDL:TC ratio (up to 8 h); ↓MDA: TAG ratio (up to 8 h); ↑ serum epigallocatechin-3-gallate (2 h); ↑ urine 3-methoxy-4-hydroxyphenylacetic acid (flavonoid metabolite, up to 24 h)pecan diet contained 1815 GAE vs 13 in the control diet. Three groups (control, whole pecan and blended pecan)Hudthagosol et al., 2010
modulate plasma lipid contentwhole pecan19 normolipidemic volunteers. Consumption of 68 g/day of pecan for 8 weeks↑ total fat and PUFA intake; ↓ TC; ↓ LDL (10% week 4, 6% week 8); ↓ HDL; ↑ Mg intake; ↔ BMI; ↔ body weightSelf-selected diet, with or without pecan. Pecan contributed with 459 Kcal and 44 g fat dailyMorgan and Clayshulte, 2000
modulate plasma lipid contentwhole pecan17 hyperlipidemic volunteers. Consumption of 68 g/day of pecan during 8 weeks↑ total fat, MUFA and PUFA intake; ↔ TC; ↔ LDL; ↔ HDL; ↔ TAG; ↔ BMI; ↔ body weightAll plasma lipid parameters decreased by week 4, but returned to control levels by week 8Eastman and Clayshulte, 2005
modulate plasma lipid contentwhole pecan24 healthy volunteers. Two diets each for 4 weeks: control diet and pecan-enriched (78 g, 20% total energy from pecan)↓ plasma α-tocopherol normalized to total cholesterol; ↑ plasma γ-tocopherol normalized to total cholesterol; ↓ plasma TBARS; ↔ FRAP, TEACrandomized, single-blind, crossover, controlled-feeding trialHaddad et al., 2006
modulate plasma lipid contentwhole pecan in a modified Step 1 diet23 healthy volunteers. Pecan diet (72 g/day, 20% energy replacement by pecan) vs Step I diet 4 weeks↓ TC (6.7%); ↓ LDL (10.4%); ↓ TAG (11.1%); ↑ HDL (5.6%) similar to baseline; ↓ LDL: HDL (15.7%); ↑ APOA1 (5.6%) similar to baseline; ↓ APOB (11.6%); ↓ lipoprotein (15.1%); ↔ body weightBoth diets improved lipid profile compared to western diet(ajaram et al., 2001

 

Table 7. biological activity by-products
 
ActivityBy-productExtractionModelResultsCommentsReference
EC50: median effective dose, IC50: inhibitory concentration for 50% of the samples, ↓: decrease compared to control, ↑: increase compared to control, ↔ no change compared to control, TC: total cholesterol, TAG: triacylglyceride, HbA1c: Glycated hemoglobin, AR: aldose reductase, MDA: Malondialdehyde, TBARS: thiobarbituric acid-reactive substances, GSH: reduced glutathione, TAC: total antioxidant capacity, AST: aspartate aminotransferase, ALT: alanine aminotransferase, GGT: GGT, gamma gluthamyl transpeptidase, CAT: catalase, SOD: superoxide dismutase, MIC: minimum inhibitory concentration, TAG: triacylglyceride, OD: orofacial dyskinesia, CP: Cyclophosphamide, STZ: streptozotocin, MCF-7: Michigan Cancer Foundation-7 cells.
anticancershellwater extractMCF-7 cellsEC50: 74.11 mg/L (MCF-7); EC50: 349.6 mg/L (3T3); ↑ antiproliferative effect; ↑ apoptotic (6.2 times); ↓cell viability (52%); ↔ necrotic cells; ↓cell in G1 and G2/M phase; ↑ plasmid DNA damagedose-dependentHilbig et al., 2018
anticancershellwater extractEhrlich ascites tumor in Balb-C mice↓tumor growth (52%); ↑ mice survival (67%); ↓ Ehrlich ascites cells viability; ↑ apoptotic (55%); ↑ pro-apoptotic proteins; ↓ anti-apoptotic proteins; ↑ Ehrlich ascites cell’s DNA damagedose-dependentHilbig et al., 2018
antidiabeticBark6 pure compounds extracted from barklenses of STZ diabetic rats↓ HbA1c; ↑ AR activity; ↑ plasma insulin level; ↑ GSH; ↓ MDA (TBARS)SAR OH CH3Abdallah et al., 2011
antidiabeticshellwater extractSTZ-induced diabetic Wistar rats. 100 mg/kg b.w. 28 days↓blood glucose; ↓blood urea; ↔ serum creatinine; no genotoxic activity in blood (Comet assay); no mutagenic effect on bone marrow (micronucleus formation)no DNA damage or increased micronucleus frequencyPorto et al., 2015a
antidiabeticShell and leavemethanol extractSTZ-induced diabetic Sprague-Dawley rats. 125 mg/kg b.w. 4 weeksLD50 > 5 gr/kg; ↓serum glucose; ↓serum HbAtc (higher than control, leaves > shell); ↔ serum insulin; ↑GSH level in diabetic rats (Leaves > Shell); ↑TAC level in diabetic rats (Leaves > Shell); ↓serum oxidative stress markers (Leaves > Shell); ↓ serum MDA (TBARS) (Leaves > Shell)Hawary et al., 2016
anti-inflammatoryshellwater extractacetic acid and carrageenan induced inflammation in male Swiss mice. Up to 1000 mg/kg b.w.↓acetic acid abdominal constriction (ID50 = 477 mg/Kg); ↓carrageenan-mediated hyperalgesia; ↓H2O2 content in carrageenan-treated mice; ↔ serum AST, ALT, Urea, Creatinineno toxic effect at the water extract concentration used. Intra-gastricTrevisan et al., 2014
antimicrobialBarkhexane extractMycobacterium tuberculosisMIC Bark extract: 31 μg/mLno effect of water, methanol or ethanol extracts. No effect of leave extractsCruz-Vega et al., 2008
antimicrobialshellmethanol extract (70%)8 plant pathogenic fungi and 10 Fusarium oxysporum isolates100% inhibition of 5 fungi and 50-75% inhibition for the other 3 fungi; 100% inhibition of 50% of Fusarium strains and 50–75% inhibition of the rest0.20 mg/L extractOsorio et al., 2010
antimicrobialshellliquid smoke of roasted or non-roasted pecan shellsSalmonella, Staphylococcus, EscherichiaMIC 6%; No inhibition with water or hexane extracts; MIC acetic acid < MIC methanol; ↓ MIC roasted PSEVan Loo et al., 2012
antimicrobialshellliquid smoke of roasted or non-roasted pecan shellsL. monocytogenes↓ MIC roasted PSE (0.38%)higher antimicrobial activity in roasted liquid smokeBabu et al., 2013
antimicrobialshellliquid smoke of roasted or non-roasted pecan shellsChicken tissue↓ chicken skin microfloratreatment before inoculationBabu et al., 2013
antimicrobialshellwater extract (infusion)L. monocytogenes, S. aureus, V. parahaemolyticus, B. cereusMIC 0.11–2.5 mg/mLLess effective against L. monocytogenesdo Prado et al., 2014
antimicrobialshellethanol extractL. monocytogenes, S. aureus, V. parahaemolyticus, B. cereusMIC 0.15–1.87 mg/mLLess effective against L. monocytogenesdo Prado et al., 2014
antimicrobialshellwater extract6 Gram+ and 4 Gram-Effective against both Gram+ and Gram- bacteriano effect against fungi, E. coliCaxambú et al., 2016
antimicrobialshellnative lettuce microorganisms↓ mesophilic bacteria (3.2 log reduction); ↓ psychrotropic bacteria (2.1 log reduction); ↔ yeastAdditive or synergic effectCaxambú et al., 2016
antimicrobialLeavewater and ethanolic extracts20 Gram +, Gram - and yeast microorganismsBoth extracts showed inhibition with MIC values between 25 and 0.78 mg/mLBottari et al., 2017
cell protectiveShellAcetone extractCGNs cellsEC50: 1.8 mg/mL; no protective effect against H2O2 oxidative stressdose-dependentde la Rosa et al., 2014
modulate plasma lipid contentshelltyloxapol-induced hypercholesterolemic Wistar rats. 100 mg/kg b.w. 28 days↓TC; ↓TAGno DNA damage or increased micronucleus frequencyPorto et al., 2015a
digestive enzymes inhibitionshellacetone extract, LH 20 columneffect of proanthocyanidins in in vitro digestive system↓ lipase (46–17.5%); ↓ amylase (28.3–44.2%); ↓ trypsin (3.9–25.1%)activity depended on ADP and prodelphinidins contentVázquez-Flores et al., 2017
hepatoprotectiveleaveethanol extractintraperitoneal CCl4 hepatic damage in Sprague Dawley rats. 100 mg/Kg extractLD50: 8.3 g/kg; ↑GSH level in diabetic rats; ↓ CCl4-induced AST, ALT and ALP levels in serumhigh antioxidant and hepatoprotective effect of extractGad et al., 2007
hepatoprotectiveshellwater extractethanol-induced liver damage in male Wistar rats↓Fe2+ oxidation in hepatic tissue (IC50 = 66.1 μg/mL, TBARS); ↓ethanol-induced body weight loss; ↓ethanol-induced micronucleus formation; ↓ethanol-induced AST, ALT and GGT levels; ↓ethanol-induced hepatic lipid oxidation (TBARS); ↓ethanol-induced GSH degradation; ↑ CAT activity; ↓ethanol-induced SOD decrease activity25 g/L pecan shell extract + 20% Ethanol 10 weeks; lower micronucleus than controlMüller et al., 2013
neuroprotectiveshellwater extractreserpine- and haloperidol-induced orofacial dyskinesia (OD) in Wistar rats. 0.6 g/Kg/day for 4 weeks↓OD (preventive effect); ↓catalepsy (preventive effect); ↓OD (reverse effect); ↔ catalepsy (reverse effect)Preventive effect: shell extract given prior drug treatment; reverse effect: shell extract given after drug treatmentTrevizol et al., 2011
protective against oxidative stressshellwater extractCyclophosphamide-induced toxicity in rats (heart, kidney, liver, bladder, plasma, erythrocytes)↓ MDA (TBARS): (kidney, liver, bladder, plasma, erythrocytes); ↑ GSH: (heart, kidney, liver, bladder, erythrocytes); ↑ Vit C: (plasma); ↑ CAT: (hearth); ↓ CP-induced injury: (bladder)5% water extract ab libitum for 30 days prior drug treatmentBenvegnú et al., 2010
protective against oxidative stressshellwater extractoxidative damage by cigarette smoke exposure in Swiss mice. 25 g/L in water, ab libitum↓smoke-induced stress behavior (motion and fecal behavior); ↓lipid peroxidation (TBARS) in brain (like control); ↓lipid peroxidation (TBARS) in red blood cells (similar to control); ↓ascorbic acid depletion in red blood cells (similar to control); ↑ CAT activity in brain; ↑ CAT activity in red blood cells (similar to smoke-treated mice); ↓body weight (compared to control); less body weight loss (compared to smoke)no toxic effect at the water extract concentration usedReckziegel et al., 2011
toxicity studiesshellwater extractWistar rats, acute single doses up to 2000 mg/kg.LD50 > 2000 mg/kg; slight toxicity signs (dyspnea, lethargy and grunting)Porto et al., 2013
toxicity studiesshellwater extractSubacute test up to 100 mg/kg for 28 days↓body weight; ↑ platelets; ↓TAG; ↓micronucleus; no mutagenic effect on S. typhimurium strainsdose-dependentPorto et al., 2013
toxicity studiesshellwater extractCF-1 male mice, acute doses up to 2000 mg/kg.EC50: 1166 mg/kg, no signs of toxicity (behavioral pattern) at lower dosesPorto et al., 2015b
toxicity studiesshellwater extractSubacute test 200 mg/kg for 3 daysHighest doses (200 mg/kg) slight changes in habituation to stress situations; no genotoxic activity (Comet assay); no mutagenic effect on bone marrow (micronucleus formation); ↔ TC, TAG, glucosePorto et al., 2015b
toxicity studiesshell fibershell powderRats (Sprague-Dawley), mice (NMRI) feed with up to 150,000 mg/kg/day for 13 weeks↔ food efficiency; ↔ hematology parameters; ↔ urinary parameters; ↔ microscopic parameters; ↔ bacterial reverse mutagenic assay; ↔ mammalian micronucleus assay; ↓ TAG in female animalsno toxic effect at the concentrations usedDolan et al., 2016