Extraction and Identification of Phytosterols in Manketti (Schinziophyton rautanenii) Nut Oil

Phytosterols of manketti (Schinziophyton rautanenii) nut oil extracted by Soxhlet, mechanical shaking using hexane, screw press and supercritical carbon dioxide, were analyzed by gas chromatography with flame ionization detection and identified by gas chromatography–mass spectrometry. The presence of several phytosterols (campesterol, stigmasterol, β‐sitosterol, Δ⁵‐avenasterol, 22‐dihydrospinasterol and Δ⁷‐avenasterol) previously reported in manketti oil, was confirmed. In addition, another fourteen phytosterols (lanosterol, Δ^5,23‐stigmastadienol, Δ⁷‐campesterol, clerosterol, obtusifoliol, Δ^5,24(25)‐stigmastadienol, α‐amyrin, gramisterol, cycloeucalenol, cycloartenol, stigmasta‐8,24‐dienol‐3‐β‐ol, 28‐methylobtusifoliol, 24‐methylenecycloartenol and citrostadienol) were identified. The phytosterols, β‐sitosterol, Δ⁵‐avenasterol and campesterol, had the highest concentrations in oils extracted by all the methods, whereas stigmasterol and cycloartenol were abundant in oils extracted by mechanical shaking and supercritical carbon dioxide. Total phytosterols and the quantities of individual phytosterols differed significantly (p ≤ 0.05) in oils from the four extraction methods. Mechanical shaking extracted the highest levels of total sterols (22,100 mg/100 g oil), followed by supercritical fluid extraction (9,550 mg/100 g oil). Screw press and Soxhlet extracted oils contained the lowest levels of total sterols, 3,810 mg/100 g oil and 3,350 mg/100 g oil, respectively.     

Noncholesterol Sterols as Surrogate Markers in Patients with Severe Alcoholic Hepatitis

Severe alcoholic hepatitis (AH) is a life‐threatening condition lacking good serologic markers to tailor treatment and predict recovery. We examined the cholesterol metabolism in severe AH to explore prognostic markers and evaluate the profile of cholesterol precursors, cholestanol and phytosterols, in this context. We assessed serum cholesterol, cholesterol precursors, cholestanol, phytosterols, and biochemical markers in 24 patients with severe AH treated with prednisolone and randomized to ciprofloxacin in the ratio 1:1. Response to prednisolone was assessed with the Lille model. Evaluations were made between responders and nonresponders to corticosteroid treatment and during follow‐up for 180 days. The findings were compared with those from patients with primary sclerosing cholangitis (PSC) (n = 156) and healthy individuals (n = 124). Responders to prednisolone had ~56–60% higher (p‐value 0.032–0.044) serum ratios to cholesterol of phytosterols, while the lathosterol/campesterol ratio was ~76% (p = 0.031) lower compared to nonresponders. Stigmasterol/cholesterol predicted response to corticosteroid therapy. Surrogate markers of cholesterol synthesis (lathosterol and desmosterol) inversely reflected those of absorption (cholestanol and phytosterols) in PSC and controls (r‐range ?0.247 to ?0.559, p < 0.01 for all), contrary to AH patients, among whom this reciprocal regulation was partially recovered on day 90 (lathosterol: r‐range ?0.733 to ?0.952, p < 0.05 for all). AH patients had ~26% lower lathosterol/cholesterol, but 1.13–3.87‐fold higher cholestanol/cholesterol and sitosterol/cholesterol compared to control groups (p < 0.05 for all). Median ferritin concentration at baseline was ~37% lower (p = 0.011) among the responders. Cholesterol precursors and phytosterols have a disease‐specific profile in AH. Phytosterols and ferritin may serve as surrogate markers for short‐term response.     

Membrane phospholipids and sterols in microfiltered milk fat globules

Native milk fat globules of various mean diameters, ranging from d₄₃ = 2.3 µm to 8.0 µm, were obtained using microfiltration of raw whole milk. After milk fat globule washing, the milk fat globule membrane (MFGM) was separated by manual churning. After total lipid extraction and separation of polar lipids, their phospholipid (PL) and sterol composition was measured using thin‐layer chromatography, methyl ester analyses by gas chromatography, and gas chromatography coupled to mass spectrometry. The main PL species were phosphatidylethanolamine, phosphatidylcholine and sphingomyelin. The respective fatty acid composition of each PL species was measured. Many different minor bioactive sterols were detected in the MFGM, e.g. lanosterol, lathosterol, desmosterol, stigmasterol and β‐sitosterol. No significant differences in the PL and sterol profile were found between MFGM extracted from small and large milk fat globule fractions.     

Effects of ketoconazole on cholesterol synthesis and precursor concentrations in the rat liver

Ketoconazole, an antimycotic agent, given to rats for a week as 0.05% food addition had no effect on the hepatic concentrations of free and esterified cholesterol or on the activity of acyl coenzyme A: cholesterol-acyltransferase (ACAT). However, the levels of free methylated cholesterol precursors, especially lanosterols, less markedly Δ^8,24 and Δ⁸-dimethyl sterols and monomethyl sterols, were increased after only one day's treatment, while those of esterified methyl sterols were increased inconsistently, and those of free and esterified Δ⁸-lathosterol, lathosterol and desmosterol were not affected at all. Cholestyramine treatment had no significant effect on ACAT in spite of a decrease in the hepatic content of esterified cholesterol and caused a marked increase in the free cholesterol precursor levels, especially in those of lathosterols. Cholestyramine given to ketoconazole-treated rats increased the hepatic levels of Δ⁸ and Δ⁷-lathosterols but not desmosterol or methylated cholesterol precursors. Ketoconazole increased and cholestyramine markedly decreased plantssterols, sitosterol and campesterol in the liver. In serum, the contents of both lanosterols and lathosterol were increased but that of cholesterol tended to be decreased by ketoconazole (−19%). The results indicate that ketoconazole impairs demethylation processes at C-14 and to some extent at C-4 in the rat liver, resulting in lowered serum cholesterol level.     

Effects of cholestyramine and squalene feeding on hepatic and serum plant sterols in the rat

Hepatic and serum phytosterol concentrations were compared in the rat under basal conditions and during activated cholesterol and bile acid production due to squalene and cholestyramine feeding. Both treatments consistently decreased hepatic and serum levels of sitosterol and campesterol and, unlike esterified cholesterol, esterified plant sterols were not increased in liver during squalene feeding. Serum levels of phytosterols were decreased quite proportionately to those in the liver. The hepatic levels of sitosterol and campesterol closely correlated with each other, but not with cholesterol levels. The percentage esterification of both phytosterols was lower than that of cholesterol. The results indicate that activation of hepatic sterol production leads to depletion of hepatic plant sterols. It is suggested that poor esterification of plant sterols may contribute to this decrease.     

Serum and aortic levels of phytosterols in rabbits fed sitosterol or sitostanol ester preparations

Campesterol is present in all the phytosterol-containing dietary hypocholesterolemic agents in current use. Campesterol is absorbed more efficiently than sitosterol, and the question of its possible atherogenicity has been raised. To test this possibility, rabbits were fed either a semipurified, cholesterol-free diet that has been shown to be atherogenic for this species or the same diet augmented with 0.5 g of phytosterol-rich diet preparations (spreads) containing either sitosterol or sitostanol. The diets contained 295 mg phytosterol per 100 g. After 60 d, serum cholesterol levels in the two phytosterol groups were 78±4 mg/dL (sitosterol) and 76±4 mg/dL (sitostanol), respectively. The serum cholesterol level of rabbits fed the control diet was 105±8 mg/dL. Serum campesterol (μg/mL) levels were higher than sitosterol or sitostanol levels in all groups. Aortic phytosterols were present in nanogram quantities compared to cholesterol, which was present in microgram quantities. The ratio of campesterol/sitosterol/sitostanol in the aortas was: control, 1.00∶0.43∶0.02; sitosterol, 1∶00∶0.32∶0.01; sitostanol, 1∶00∶0.34∶0.11. Aortic campesterol was present at 4% the concentration of aortic cholesterol, sitosterol at 1.4%, and sitostanol at 0.14%. Aortic lesions were not present in any of the animals.     

Comparative analysis of phytosterol components from rapeseed (Brassica napus L.) and olive (Olea europaea L.) varieties

Phytosterols occur in relatively high concentration in the seeds of rapeseed (Brassica napus L.) and in lower concentration in olive (Olea europaea L.) oil. The aim of this research was to investigate some new rapeseed varieties and olive genotypes that are grown in Northwest Turkey and to compare the phytosterol contents of both crops. For rapeseed, the data were collected in the growing seasons 2004–2005 from a field experiment with 19 new rapeseed varieties and three replications. For olives, 21 different varieties were used in the 2004–2005 and 2005–2006 growing seasons. The separation and identification of free phytosterols and the analysis of their contents were successfully achieved using the capillary column‐gas chromatographic method. According to the obtained results, for rapeseed, sitosterol (1.54–2.36 g/kg) was the major component of total phytosterols, followed by campesterol (0.02–1.58 g/kg) and brassicasterol (0.26–0.58 g/kg). Regarding the olive varieties, the sitosterol content changed between 1.03 and 2.01 g/kg, followed by avenasterol ranging from 0.07 to 0.44 g/kg. The brassicasterol, campesterol and stigmasterol contents did not affect the total amount of sterols. The total phytosterol content ranged between 4.25 and 11.37 g/kg for rapeseed and 1.29 and 2.38 g/kg for olives.     

Aging Induces Tissue-Specific Changes in Cholesterol Metabolism in Rat Brain and Liver

Disturbance of cholesterol homeostasis in the brain is coupled to age-related brain dysfunction. In the present work, we studied the relationship between aging and cholesterol metabolism in two brain regions, the cortex and hippocampus, as well as in the sera and liver of 6-, 12-, 18- and 24-month-old male Wistar rats. Using gas chromatography-mass spectrometry, we undertook a comparative analysis of the concentrations of cholesterol, its precursors and metabolites, as well as dietary-derived phytosterols. During aging, the concentrations of the three cholesterol precursors examined (lanosterol, lathosterol and desmosterol) were unchanged in the cortex, except for desmosterol which decreased (44 %) in 18-month-old rats. In the hippocampus, aging was associated with a significant reduction in lanosterol and lathosterol concentrations at 24 months (28 and 25 %, respectively), as well as by a significant decrease of desmosterol concentration at 18 and 24 months (36 and 51 %, respectively). In contrast, in the liver we detected age-induced increases in lanosterol and lathosterol concentrations, and no change in desmosterol concentration. The amounts of these sterols were lower than in the brain regions. In the cortex and hippocampus, desmosterol was the predominant cholesterol precursor. In the liver, lathosterol was the most abundant precursor. This ratio remained stable during aging. The most striking effect of aging observed in our study was a significant decrease in desmosterol concentration in the hippocampus which could reflect age-related reduced synaptic plasticity, thus representing one of the detrimental effects of advanced age.     

Sterols and Stanols in Foods and Dietary Supplements Containing Added Phytosterols: A Collaborative Study

An international, multilaboratory collaborative study was carried out to evaluate the performance of Official Method Ce 12‐16 of the American Oil Chemists’ Society (AOCS) for the determination of plant sterols and stanols, collectively referred to as phytosterols, in foods and dietary supplements containing added phytosterols and in the phytosterol food additive concentrates used to prepare such products. AOCS Official Method Ce 12‐16 involves the extraction of free sterols/stanols and saponified steryl/stanol esters followed by the gas chromatographic separation and flame ionization detection of phytosterol trimethylsilyl ether derivatives. A total of 14 laboratories from six countries successfully completed the analysis of collaborative samples of foods (e.g., baked goods, beverages, margarines; n = 9), dietary supplements (n = 5), and phytosterol concentrates (n = 4). Study results for the contents of total phytosterols (weight/weight) were 0.19–8.4% for foods, 8.7–49% for dietary supplements, and 57–97% for concentrates. AOCS Official Method Ce 12‐16 showed acceptable performance for total and individual phytosterols, indicating that this method was suitable for the determination of added phytosterols in a wide variety of market products and concentrates. AOCS Official Method Ce 12‐16 is appropriate for the determination of the five major phytosterols (i.e., campesterol, stigmasterol, β‐sitosterol, campestanol, and sitostanol) that are the subject of the United States Food and Drug Administration's health claim for phytosterols and the reduced risk of coronary heart disease.     

Soybean germ oil inhibits oxidosqualene cyclase in 3T3 fibroblasts

Soybean germ oil (SGO) could take an important place among nutraceuticals if the finding were confirmed that a daily intake of SGO helps to maintain a normal level of serum cholesterol. Adapting the rice milling technology to the soybean refining process, we achieved a rapid and efficient separation of soybean bran and cotyledon from the hypocotyle. Our soybean germ was no less than 95% hypocotyle. SGO obtained from it by typical hexane extraction was very rich in tocopherols (total content 4.35 g/kg) and phytosterols (β‐sitosterol 57.4%, Δ‐7‐stigmastenol 20.2%, Δ‐7‐avenasterol 6.8%, stigmasterol 6.2%, campesterol 5.4%, Δ‐7‐campesterol 1.2%, Δ‐5‐avenasterol 0.95%, etc.; total sterols 44.3 g/kg). The most prominent fatty acids were linoleic (56.2%), linolenic (15.5%) and oleic acid (10.6%). Although isoflavones abound in soybean germ (17.7 g/kg), only traces of them passed into the hexane extract (7 mg/kg). In murine 3T3 fibroblasts, SGO was found to reduce the incorporation of [¹⁴C]acetate into sterols, by inhibiting oxidosqualene cyclase.     

Sterol metabolism in the nematodeCaenorhabditis elegans

The metabolism of various dietary sterols and the effects of an azasteroid on sitosterol metabolism in the free-living nematodeCaenorhabditis elegans was investigated. The major unesterified sterols ofC. elegans in media supplemented with sitosterol, cholesterol or desmosterol included 7-dehydrocholesterol (66.5%, 40.5%, 31.2%, respectively), cholesterol (6.7%, 52.3%, 26.9%), lathosterol (4.4%, 3.6%, 1.7%) and 4α-methylcholest-8(14)-en-3β-ol (4.2%, 2.1%, 3.8%). Esterified sterols, representing less than 20% of the total sterols, were somewhat similar except for a significantly higher relative content of 4α-methylcholest-8(14)-en-3β-ol (23.3%, 23.4%, 10.6%). ThusC. elegans not only removes the substituent at C24 of dietary sitosterol but possesses the unusual ability to produce significant quantities of 4α-methylsterols. WhenC. elegans was propagated in medium supplemented with sitosterol plus 5 μg/ml of 25-azacoprostane hydrochloride, the azasteroid strongly interfered with reproduction and motility ofC. elegans and strongly inhibited the Δ24-sterol reductase enzyme system; excluding sitosterol, the major free sterols of azacoprostane-treatedC. elegans were cholesta-5, 7, 24-trien-3β-ol (47.9%), desmosterol (9.4%), fucosterol (2.1%) and cholesta-7,24-dien-3β-ol (2.0%). These 4 sterols are likely intermediates in the metabolism of sitosterol inC. elegans.     

Chemical evaluation of some paprika (Capsicum annuum L.) seed oils

The oil contents of seeds from paprika (Capsicum annuum L.) collected from different locations in Turkey and Italy varied in a relatively wide range from 8.5 g/100 g to 32.6 g/100 g. The fatty acid, tocopherol and sterol contents of the oils from different paprika seeds were investigated. The main fatty acids in paprika seed oils were linoleic acid (69.5–74.7 g/100 g), oleic acid (8.9–12.5 g/100 g) and palmitic acid (10.7–14.2 g/100 g). The oils contained an appreciable amount of γ‐tocopherol (306.6–602.6 mg/kg), followed by α‐tocopherol (7.3–148.7 mg/kg). The major sterols were β‐sitosterol (1571.4–4061.7 mg/kg), campesterol (490.8–1182.7 mg/kg), and Δ⁵‐avenasterol (374.5–899.6 mg/kg). The total concentration of sterols ranged from 3134.0 mg/kg to 7233.7 mg/kg. Remarkable amounts of cholesterol were found in the different samples (164.6–491.0 mg/kg). The present study showed that paprika seeds are a potential source of valuable oil that could be used for edible and industrial applications.     

Microbial conversion of sterol‐containing soybean oil production waste

Soybean extract residue (scum), a waste of soybean oil production, was examined as a raw material for C₁₇‐ketosteroid production. As a model process, its bioconversion to 9α‐hydroxyandrost‐4‐ene‐3,17‐dione (9‐OH‐AD) by Mycobacterium sp VKM Ac‐1817D was studied. The content of transformable sterols (sitosterol, stigmasterol and campesterol) in scum was estimated at ～14%. The bioconversion of scum to 9‐OH‐AD was characterized by a long lag‐period (300–350 h) followed by 9‐OH‐AD accumulation. The microbial or chemical elimination of fatty non‐identified components resulted in sterol‐enriched scum preparations. Effective conversion of these preparations by Mycobacterium sp was demonstrated: 9‐OH‐AD molar yield ～65% was reached at 60 h from the scum preparation containing 10 g dm^?3 transformable sterols. The process productivity was comparable with that for high quality‐sitosterol of wood origin (tall‐oil sitosterol). Copyright © 2004 Society of Chemical Industry     

Composition of Catalpa ovata Seed Oil and Flavonoids in Seed Meal as Well as Their Antioxidant Activities

In view of the growing demand for vegetable oil, currently exploration of some non‐conventional oils is of great concern. This study firstly analyzed the contents of fatty acids, phytosterols, and tocopherols in Catalpa ovata seed oil collected from four different Provinces in China. Then the composition of flavonoids as well as their antioxidant activities in defatted seed meal was determined. The results showed that the relative oil content in C. ovata seeds ranged from 24.0 to 36.0 % and seed oil was mainly composed of fatty acids linoleic acid (43.4–50.1 %), α‐linolenic acid (23.8–24.4 %), and oleic acid (13.1–16.2 %). The content of unsaturated fatty acids was up to 85.0 %. Sterol in seed oil mainly contained campesterol, stigmasterol, and β‐sitosterol. β‐sitosterol accounted for 74.0 % of the total sterol. The tocopherol content was 173.0–225.7 mg/100 g. Defatted seed meal from Hubei Province showed the highest content of total flavonoids (11 mg/g) and the strongest activities for DPPH radicals scavenging, ABTS radicals scavenging, and ferric reducing antioxidant power compared with other defatted seed meal in this study. Seven flavonoids were identified from C. ovata seed meal. These results suggest that C. ovata seeds may be developed as a new source of oil and can also be properly used in pharmaceuticals and cosmetics.     

The Content and Composition of Total,Free, and Esterified Sterols of Lotus Plumule Oil by GC–MS/FID

This study investigated the content and composition of total, free, and esterified sterols of three varieties of lotus plumule oil (Hunan lotus, Jiangxi lotus, and Fujian lotus) using GC–MS/FID. The fatty acid composition of sterol fatty acid esters (SFAE) was also analyzed and compared with that of triglycerides. Results showed that total sterol of lotus plumule oil (12.10–14.21 g/100 g) was higher than that of other plant oils (corn germ oil, 1.11 g/100 g; rapeseed oil, 0.78 g/100 g). No significant difference was found among the total sterol contents of the three types of lotus plumule oils (p > 0.05). Most sterol existed in ester forms (81.8–89.1%) rather than in free forms (8.4–10.1%). β‐Sitosterol (71.4–73.4%), and campesterol (6.2–7.5%) were the predominant fractions of free sterols. β‐Sitosterol (41.3–53.7%) and ?5‐avenasterol (27.1–31.1%) were the predominant fractions of esterified sterols, followed by campesterol (12.1–13.0%) and ?7‐avenasterol (3.4–3.7%). Linoleic acid (63.6–65.8%), oleic acid (8.3–10.4%), and behenic acid (9.0–9.9%) were the main fatty acids of SFAE, which were different from those of triglycerides. The results from this study suggest that lotus plumule oil may be a good resource of SFAE and can be used as a supplemental ingredient in functional foods.     

Phytosterol Esterification is Markedly Decreased in Preterm Infants Receiving Routine Parenteral Nutrition

Several studies reported the association between total plasma phytosterol concentrations and the parenteral nutrition‐associated cholestasis (PNAC). To date, no data are available on phytosterol esterification in animals and in humans during parenteral nutrition (PN). We measured free and esterified sterols (cholesterol, campesterol, stigmasterol, and sitosterol) plasma concentrations during PN in 16 preterm infants (500–1249 g of birth weight; Preterm‐PN), in 11 term infants (Term‐PN) and in 12 adults (Adult‐PN). Gas chromatography–mass spectrometry was used for measurements. Plasma concentrations of free cholesterol (Free‐CHO), free phytosterols (Free‐PHY) and esterified phytosterols (Ester‐PHY) were not different among the three PN groups. Esterified cholesterol (Ester‐CHO) was statistically lower in Preterm‐PN than Adult‐PN. Preterm‐PN had significantly higher Free‐CHO/Ester‐CHO and Free‐PHY/Ester‐PHY ratios than Adult‐PN (Free‐CHO/Ester‐CHO: 1.1 ± 0.7 vs. 0.6 ± 0.2; Free‐PHY/Ester‐PHY: 4.1 ± 2.6 vs. 1.3 ± 0.8; *P < 0.05). Free‐CHO/Ester‐CHO and Free‐PHY/Ester‐PHY ratios of Term‐PN (Free‐CHO/Ester‐CHO: 1.1 ± 0.4; Free‐PHY/Ester‐PHY: 2.9 ± 1.7) were not different from either Preterm‐PN or from Adult‐PN. Plasma Free‐CHO/Ester‐CHO and Free‐PHY/Ester‐PHY were unchanged after 24 h on fat‐free PN both in Preterm‐PN and in Adult‐PN. Free‐PHY/Ester‐PHY did not correlate with phytosterol intake in Preterm‐PN. Free‐PHY/Ester‐PHY of Preterm‐PN was positively correlated with the Free‐CHO/Ester‐CHO and negatively correlated with gestational age and birth weight. In conclusion, PHY were esterified to a lesser extent than CHO in all study groups; the esterification was markedly decreased in Preterm‐PN compared to Adult‐PN. The clinical consequences of these findings warrant further investigations.     

Stabilization of phytosterols in rapeseed oil by natural antioxidants during heating

Antioxidants are substances that can reduce negative changes in fat. Many antioxidants are very effective during storage, but during heating they lose their properties. It is very important to find antioxidants that will be stable at high temperatures and protect fat throughout the entire frying process. The aim of this study was to estimate the effect of natural and synthetic antioxidants on changes in phytosterols of rapeseed oil during heating. Oil with antioxidants was heated at 180 °C for 4 h in a Rancimat® and in an Oxidograph®. Ethanol extract of rosemary, ethanol extract of green tea, and BHT were used in the study. The contents of phytosterols (sitosterol, campesterol, avenasterol, brassicasterol, stigmasterol) and oxyphytosterols (7α‐ and 7β‐hydroxysterol, 5α,6α‐ and 5β,6β‐epoxysterol, 7‐ketosterol and triols) were estimated by gas chromatography. In all samples with antioxidants, a lower decrease of phytosterols and a lower increase of total oxyphytosterols were observed in comparison with the control sample (without antioxidant). The antioxidant effect depends on the type of the antioxidant and the heating conditions. The best results were observed in samples with natural antioxidants. BHT was a substance that protected phytosterols as well, but not as effectively as the other antioxidants.     

Assessment of Sterol Oxidation in Oils Recovered from Exhausted Bleaching Earth by Coupled Capillary Column GC and GC–MS Methods

Cholesterol and phytosterols are generally present in foods at ppm levels and they can generate many oxidation products, i.e. oxysterols. The oxysterols comprise only a small percentage of unoxidized sterols. Reliable quantitative data on these compounds requires reasonably good separation by capillary column GC. The present study attempts to overcome the difficulties involved in separating many common oxysterols generated from cholesterol, brassicasterol, campesterol, stigmasterol, and sitosterol by coupling two high-resolution GC capillary columns. The columns, DB-17MS and DB-35MS, were coupled separately to a DB-5MS column. Total separation time of the authentic samples of oxysterols was 41 min for the DB-35MS/DB-5MS and 44 min for the DB-17MS/DB-5MS coupled columns. Two oil samples EBE1 and EBE2 extracted from exhausted bleaching earth collected from Europe were analyzed for oxysterol content by using these column combination systems. Both systems showed similar quantitative results; the total levels of oxysterols in these samples ranged from 2 to 3 mg/100 g. The prominent oxysterols were as follows: 7α-hydroxysterols (0.29–0.49 mg/100 g), 7β-hydroxysterols (0.13–0.68 mg/100 g) and 7-ketosterols (0.63–0.69 mg/100 g).     

Separation of Campesterol and β‐Sitosterol from a Sterol Mixture

Abstract

By solvent crystallization using diethyl ether as the solvent on sterol mixture, brassicasterol and stigmasterol that contains a side chain with double bond were separated from campesterol and β‐sitosterol with a saturated side chain. The total campesterol and β‐sitosterol content in the liquid phase was more than 97% with a recovery of 12%. Multistage crystallization using acetone as the solvent could increase the recovery of campesterol and β‐sitosterol to 30%. By employing zeolite selective adsorption on the campesterol and β‐sitosterol fraction, β‐sitosterol can be recovered in the liquid phase with a purity of 95.2% and a recovery of 3% (overall recovery 1%). After desorbing in ethanol, campesterol adsorbed on the zeolite can be recovered with a purity of 95.4% and a recovery of 3.7% (overall recovery 1.6%).     

Bleaching augments lipid peroxidation products in pistachio oil and its cytotoxicity

Pistachio consumption is associated with reductions in serum cholesterol and oxidative stress due to their constituents of unsaturated fats, phytosterols, fiber, and antioxidants. Bleaching has been applied to whiten nut shells for antifungal and cosmetic purposes. However, the impact of bleaching on nutritional quality and safety of pistachios remains to be examined. In this study, we investigated whether bleaching would increase malondialdehyde (MDA) or 7‐keto‐sitosterol and decrease phytosterols in pistachio oil, as well as cause cytotoxicity of modeled Hepa1c1c7 cells. Bleaching increased MDA by more than 32% from 0.23 µg/g in raw oil, with the largest increase noted with the bleach containing H₂O₂ and Fe²⁺ (P ≤ 0.05). Bleached pistachio oil had larger than 12.6% decrease in β‐sitosterol and total phytosterols as compared to the raw oil (P ≤ 0.05). Bleaching with Fe²⁺ significantly increase 7‐keto‐sitosterol compared to bleaching alone. Hepatic cell viability was decreased the most by the oil of the pistachios treated with bleach containing Fe²⁺ (P ≤ 0.05), and lactate dehydrogenase activity in medium was elevated by >18‐folds (P ≤ 0.05). Compared to natural pistachios, the bleaching treatment had detrimental effects on nutritional quality and expected health benefits of pistachios by increasing lipid peroxidation, decreasing phytosterol content, and causing cytotoxicity. Practical applications: Bleaching has been applied to whiten the nut shell for antifungal and cosmetic purposes. However, the results of this study indicate that bleaching treatment has a detrimental impact on nutritional quality and expected health benefits of pistachios. Particularly, treatment with a bleach formula with hydrogen peroxide and transit metals increases formation of lipid peroxidation products and decreases phytosterol content. The resulting pistachio oil causes cell toxicity. Thus, bleaching practice for whitening pistachios is strongly discouraged.