Nutraceutical functions of sesame: a review

The results of recent food chemical and nutraceutical studies on the traditionally well-known health value of sesame are described, including some aspects of the utilization of sesame. The highly antioxidative activity of sesame oil was clarified and found to involve newly discovered lignans. The antiaging effect of sesame was elucidated to be due to the strong vitamin E activity caused by a novel synergistic effect of sesame lignans with tocopherols resulting from the inhibition of metabolic decomposition of tocopherols by sesame lignans. The specific inhibitory action of sesame lignans on Delta5 desaturase in polyunsaturated fatty acid synthesis was found in studies on the microbial production of polyunsaturated fatty acids. This effect of sesame lignans was extended to various effects on fatty acid metabolism involving lowering fatty acid concentration in liver and serum due to acceleration of fatty acid oxidation and suppression of fatty acid synthesis, and the controlling influence on the ratio of n-6/n-3 polyunsaturated fatty acids under excess intake of either n-6 or n-3 fatty acids in the diet. Sesame lignans lowered the cholesterol concentration in serum, especially in combination with tocopherol, due to the inhibition of absorption from the intestine and suppression of synthesis in the liver. Sesame lignans also showed other useful functions such as acceleration of alcohol decomposition in the liver, antihypertensive activity, immunoregulatory activities, anticarcinogenic activity, and others.     

Variation of sesamin,sesamolin and tocopherols in sesame (Sesamum indicum L.) seeds and oil products in Thailand

Sesame (Sesamum indicum L.) seed and oil contain abundant lignans, including sesamin, sesamolin and lignan glycosides. The aim of the present study was to determine sesamin, sesamolin and tocopherol contents in sesame seed and oil available in Thailand. The results showed that there was a large variation of sesamin and sesamolin contents in products. The distribution plot of sesamin and sesamolin contents in seeds showed that the mean values of sesamin and sesamolin were 1.55 mg/g (SD = 1.63; range n.d.–7.23 mg/g) and 0.62 mg/g (SD = 0.48; range n.d.–2.25 mg/g), respectively. The range of total tocopherols of these sesame lines was 50.9–211 μg/g seed. In commercial sesame oils, the ranges of sesamin and sesamolin were 0.93–2.89 mg/g oil and 0.30–0.74 mg/g oil, respectively, and tocopherol contents were 304–647 μg/g oil. The study reveals the extensive variability in sesamin, sesamolin and tocopherol contents among sesame products.     

Nutritional value of sesame seeds

Literature data on the nutritional value of sesame seeds (Sesamum indicum L.), their use in feeding the world population and food production are presented. Sesame seeds contain up to 55% oil and 20% protein. Sesame proteins are limited by lysine but rich in tryptophan and methionine. Sesame oil is rich in linoleic and oleic acids, the predominance of gamma-tocopherol over the other isomers of vitamin E and high content of fat-soluble lignans (sesamin and sesamolin). Thanks to recent sesame oil has a phytoestrogen activity; it has a cholesterol-lowering effect.     

The relationship of antioxidant components and antioxidant activity of sesame seed oil

Although sesame seed oil contains high levels of unsaturated fatty acids and even a small amount of free fatty acids in its unrefined flavored form, it shows markedly greater stability than other dietary vegetable oils. The good stability of sesame seed oil against autoxidation has been ascribed not only to its inherent lignans and tocopherols but also to browning reaction products generated when sesame seeds are roasted. Also, there is a strong synergistic effect among these components. The lignans in sesame seed oil can be categorized into two types, i.e. inherent lignans (sesamin, sesamolin) and lignans mainly formed during the oil production process (sesamol, sesamolinol, etc.). The most abundant tocopherol in sesame seed oil is γ‐tocopherol. This article reviews the antioxidant activities of lignans and tocopherols as well as the browning reaction and its products in sesame seed and/or its oil. It is concluded that the composition and structure of browning reaction products and their impacts on sesame ingredients need to be further studied to better explain the remaining mysteries of sesame oil. © 2014 Society of Chemical Industry     

芝麻木脂素生物活性及其作用机制

芝麻木脂素广泛存在于芝麻籽和芝麻油中,具有较强抗氧化活性,在生物体内具有降血脂、降血糖、稳定血压,保护肝脏、抗菌防腐和抗癌抑瘤等多种生物活性。该文综述芝麻木脂素化学结构、生物活性及其作用机制,对芝麻木脂素进一步开发研究具有一定参考价值。     

Antioxidative activity of the crude extract of lignan glycosides from unroasted Burma black sesame meal

Sesame seed contains lignans and lignan glycosides. The antioxidative activity of the crude extract of lignan glycosides obtained from unroasted defatted black sesame seeds was investigated in this study. The components responsible for the antioxidative activity were also studied. The unroasted black sesame seeds, after defatted with n-hexane, were extracted with 80% methanolic solution to prepare for the crude extract of lignan glycosides. After chromatographic separation of this crude extract with octadecylsilane (ODS) column (2.5 cm i.d.×100 cm), four fractions (Fr1, Fr2, Fr3, Fr4) of the crude extract were obtained from the eluents of 25, 50, 75% aqueous methanolic solution and 100% methanol, respectively. Among them, Fr2 and Fr3 showed better antioxidative activity by 2,2-Diphenyl-1-picrylhydrazyl hydrate (DPPH) antioxidative assay. These two fractions were further purified by preparative HPLC (Hyperprep 100 C18 column; 20 mm i.d.×250 mm) and the main constituents were found to be lignan glycosides and some unknown brown materials. It was interesting to find that the brown materials (in Fr2) exhibited exceptional DPPH free radical scavenging effect, whereas the identified sesaminol triglucoside in Fr2 and sesaminol diglucoside in Fr3 possess no such activity. Using Cu⁺²-induced oxidation of human low-density lipoprotein (LDL) for the antioxidative assay, similar results were observed. Seaminol triglucoside and sesaminol diglucoside showed no effect on the extension of lag phase, while the brown materials had excellent inhibitory effect on the oxidation of LDL. Furthermore, natural antioxidants such as γ-tocopherol, sesamol and sesaminol were not detected in the crude extract of lignan glycosides. Our findings suggest that the brown materials present in Fr2 had a significant contribution to the antioxidative activity of the crude extract of lignan glycosides. Identification of the responsible components is underway.     

The contents of lignans in commercial sesame oils of Taiwan and their changes during heating

Sesame lignans have multiple functions and were recently reported to have potential as sources of phytoestrogens. Sesame oils used in Taiwan are expelled from roasted sesame seeds with dark colour and strong flavour. This study analyzed lignan contents of 14 brands of sesame oils, and found their mean of total lignans to be 11.5 mg/g; 82% and 15% of the lignans were sesamin, and sesamolin, respectively. Sesamol contents were relatively higher in those with darker colour. In use as a cooking oil, heating at 180 °C for 4 min did not change the content of lignans, but the level of sesamol increased after heating at 180 °C for 20 min. Heating at 200 °C for 20 min caused a significant loss of sesamolin and sesamol. From our calculation, ingestion of 10 g of sesame oil is adequate to provide the level of lignans that might benefit cardiovascular health, as found by other studies. Cooking at temperatures above 200 °C will cause loss of some lignans, but sesamin, a source of phytoestrogen, is relatively heat-stable.     

Effect of endogenous antioxidants of sesame seeds and sesame oil to the thermal stability of edible vegetable oils

Differently processed sesame seeds were used for the preparation of sesamol, seed extract, oil extract or unsaponifiable matter. Analysis of these sesame extracts revealed that dehulling and roasting of seeds had an adverse effect on their lignan and phenolic compounds content. Various concentrations of the extracts were incorporated in vegetable oils and their effectiveness in retarding the oxidative deterioration of oils was evaluated. Additionally, the formation of oxidation products in these oil samples was correlated with their antioxidant activity and their sesamol and phenolic compounds content. Results indicated that decomposition of phenolic compounds present in oil samples induced a significant reduction in their linoleic acid peroxidation inhibition capacity and a corresponding increase in their oxidative rancidity. Sesame seed extract was the most effective in protecting oils from oxidation, suggesting that seed extract, especially the one prepared from coated-unroasted sesame seeds, may have potential application as a source of natural antioxidants in oil industry.     

Effects of Sesame Oil Addition to Soybean Oil During Frying on the Lipid Oxidative Stability and Antioxidants Contents of the Fried Products During Storage in the Dark

ABSTRACT: Effects of sesame oil addition to soybean oil during frying on the lipid oxidative stability and antioxidants contents of fried products during storage in the dark were studied. Flour dough pieces (2 cm × 2 cm × 0.1 cm) were fried at 160 °C for 1 min in sesame oil-added soybean oil. Concentrations of sesame oil in the frying oil were 0%, 10%, and 20% by volume. Fried products were put into a glass bottle, and the bottles were tightly sealed and stored at 60 °C in the dark for 18 d. Lipid oxidation of fried products was determined by fatty acid composition changes and conjugated dienoic acid (CDA) and p -anisidine (PA) values. Tocopherols and lignan compounds in the fried products were determined by high-performance liquid chromatography. Relative content of linolenic acid decreased, and CDA and PA values increased during storage of the fried products in the dark. Fatty acid composition change and CDA and PA values during storage were lower in the products fried in sesame oil-added soybean oil than in the products fried in soybean oil without sesame oil. The results clearly showed that addition of roasted sesame oil to soybean oil at 10% and 20% during frying decreased the lipid oxidation of fried products during storage in the dark for 18 d by extension of induction period and decrease in decomposition of oxidized lipids. Fried products contained 134 to 267 ppm tocopherols and 0 to 148 ppm lignans before storage; however, their contents decreased during storage in the dark. Lignan compounds were more stable than tocopherols, and the rate of tocopherols degradation was lower in the products fried in sesame oil-added soybean oil than in the products fried in soybean oil without sesame oil, which could be because of protection of tocopherols from degradation by lignan compounds.     

APPLICATION OF SEMIPREPARATIVE RP-18 HPLC FOR THE PURIFICATION OF SESAMIN AND SESAMOLIN

A relatively simple chromatographic protocol was established to provide good separation of the unsaponifiable constituents from the seed oil of Sesamum indicum Linn. The protocol employs classical column chromatography using alumina and petroleum ether to collect furofuran lignans from sesame oil. Semipreparative RP-18 HPLC was used to separate the sesamin and sesamolin constituents in high purity (> 99%). The purity and identity of the separated compounds was confirmed by rechromatography using an analytical HPLC set up and GC-MS, respectively. The method described offers a means to isolate and collect sesamin and sesamolin in high purity for use as standards in furofuran lignan studies of sesame seed oil.     

EFFECTS OF SESAME LIGNAN EXTRACT ON LINOLEIC ACID, LIPID OXIDATION, COLOR AND TEXTURAL PROPERTIES OF GROUND PORK, AND SAUSAGE PRODUCTS

Sesame lignan extract was prepared from roasted sesame oil and added at 0.02, 0.05, 0.10 and 0.20% (w/w) to linoleic acid and ground pork products. Cooked ground pork containing more than 0.02% of lignan extract showed TBA values lower than those containing butylated hydroxyanisole (BHA) during storage. Sausages containing 0.05% of lignan extract had lower thiobarbituric acid (TBA) values when stored at 4C for 14 days; they also showed higher CIE color values than the control meat sample (P < 0.05). There were no differences in textural properties such as hardness, cohesiveness and chewiness between the control and the sausages containing lignan extract when determined by Instron Testing Machine. Thus, lignan extract prepared from roasted sesame oils was highly antioxidative when used in cooked ground pork at > 0.02% or in sausages at > 0.05%.     

芝麻中木脂素的组成、结构及其生理功能

介绍了芝麻中木脂素类物质(lignans):芝麻素、芝麻林素、芝麻酚以及芝麻林素酚等生物活性物质的结构、含量以及其所具有的抗氧化、抗癌、保护肝脏、降低血浆中的胆固醇、调节脂质代谢等诸多生理功能特性.     

Effect of Infrared Heating on the Formation of Sesamol and Quality of Defatted Flours from Sesamum indicum L.

ABSTRACT:  Infrared (IR) heating offers several advantages over conventional heating in terms of heat transfer efficiency, compactness of equipment, and quality of the products. Roasting of sesame seeds degrades the lignan sesamolin to sesamol, which increases the oxidative stability of sesame oil synergistically with tocopherols. IR (near infrared, 1.1 to 1.3 μm, 6 kW power) roasting conditions were optimized for the conversion of sesamolin to sesamol. The resultant oil was evaluated for sesamol and tocopherol content as well as oxidative stability. The defatted flours were evaluated for their nutritional content and functionality. IR roasting of sesame seeds at 200 °C for 30 min increased the efficiency of conversion of sesamolin to sesamol (51% to 82%) compared to conventional heating. The γ-tocopherol content decreased by 17% and 25% in oils treated at 200 and 220 °C for 30 min, respectively. There were no significant differences in the tocopherol content and oxidative stability of the oil. Methionine and cysteine content of the flours remained unchanged due to roasting. The functional properties of defatted flours obtained from either IR roasted or conventionally roasted sesame seeds remained the same.
Practical Applications: Sesame oil is stable to oxidation compared to other vegetable oils. This stability can be attributed to the presence of tocopherols and the formation of sesamol, the thermal degradation product of sesamolin—a lignan present in sesame. Roasting of sesame seeds before oil extraction increases sesamol content which is a more potent antioxidant than the parent molecule. The conversion efficiency of sesamolin to sesamol is increased by 31% by infrared roasting of seeds compared to electric drum roasting. This can be used industrially to obtain roasted oil with greater oxidative stability.     

微波预处理对芝麻油中芝麻木酚素含量及油脂品质的影响

为了确定高芝麻酚芝麻油的最适微波预处理条件,将芝麻水分含量调节为5个梯度,在不同微波预处理时间下制得芝麻油样品,对其芝麻木酚素含量、酸值、茴香胺值、氧化诱导时间、脂肪酸组成、生育酚含量、有害物质（多环芳烃和杂环胺）含量及感官品质进行了分析,探究芝麻水分含量和微波预处理时间对芝麻油中芝麻木酚素含量及油脂品质的影响。结果表明：微波预处理时间6 min、芝麻水分含量7%条件下制得的芝麻油芝麻酚含量较高,芝麻油酸值符合国家标准限定要求,氧化稳定性较强,有害物质杂环胺和多环芳烃含量处于适当的可控水平,同时兼顾了芝麻油的固有风味,消费者的喜爱度较高。综上,高芝麻酚芝麻油的最适微波预处理条件为微波预处理时间6 min,芝麻水分含量7%。     

亚麻木酚素解聚增效及油相迁移特性研究进展

木酚素是亚麻籽中极具代表性的活性物质,具有抗氧化、抗炎、抗癌、抗血管疾病等多种生理功能。在亚麻籽内,游离态木酚素较少,多数与其他分子结合以多聚体形式存在;大多数木酚素存在于种皮中,在压榨制油时难以释放。多聚体的存在和亚麻壳的束缚作用,都限制了亚麻籽木酚素的有效利用。本文结合近几年的研究报道,重点从萌发、物理场处理、酶以及酸碱水解的角度,对亚麻木酚素大分子的解聚增效特性、油相迁移特性及相关应用研究进行阐述,以期为亚麻籽中木酚素的靶向调控、高值化利用提供理论依据。     

Chemical Composition and Antioxidant Capacity of Brazilian Passiflora Seed Oils

The seed oils of different varieties of 4 Passiflora species cultivated in Brazil were analyzed and compared regarding their physicochemical parameters, fatty acid composition and the presence of minor components, such as phytosterols, tocopherols, total carotenoids, and phenolic compounds. The antioxidant capacities of the oil extracts were determined using the 2,2'azinobis [3‐ethylbenzothiazoline‐6‐sulfonic acid] and oxygen radical absorbance capacity methods. The results revealed that all studied Passiflora seed oils possessed similar physicochemical characteristics, except for color, and predominantly contained polyunsaturated fatty acids with a high percentage of linolenic acid (68.75% to 71.54%). Other than the total phytosterol content, the extracted oil from Passiflora setacea BRS Pérola do Cerrado seeds had higher quantities (% times higher than the average of all samples), of carotenoids (44%), phenolic compounds (282%) and vitamin E (215%, 56%, 398%, and 100% for the α‐tocopherol, β‐tocopherol, γ‐tocopherol, and δ‐tocopherol isomers, respectively). The methanolic extracts from Passiflora setacea BRS Pérola do Cerrado seed oil also showed higher antioxidant activity, which was positively correlated with the total phenolic, δ‐tocopherol, and vitamin E contents. For the first time, these results indicate that Passiflora species have strong potential regarding the use of their seeds for oil extraction. Due to their interesting composition, the seed oils may be used as a raw material in manufacturing industries in addition to other widely used vegetable oils.     

芝麻木脂素研究进展

芝麻木脂素类物具有优越抗氧化性和多种生理功能,在食品、化妆品及医药等领域具有良好应用前景。该文综述芝麻木脂素类物及其化学结构、生理功能、含量及相互转化、提取、检测方法;以期为芝麻木脂素产品开发利用提供参考。     

Evaluation of a Microwave-Assisted Extraction Method for Lignan Quantification in Flaxseed Cultivars and Selected Oil Seeds

An optimized microwave-assisted extraction (MAE) method was evaluated through repeatability, recovery and efficiency testing. The repeatability tests, performed by three users over time, were not significantly different. The recovery of lignan throughout the extraction, preparation and analysis steps is 97.5% with a coefficient of variation <1%. The MAE method is efficient for extracting lignans from the plant matrix, and it achieves significantly higher extraction yields than the two established reference methods. The applicability of the MAE method was demonstrated by extracting lignans from a variety of plant samples. The secoisolariciresinol diglucoside (SDG) content of seven flaxseed cultivars grown in Saint-Mathieu-de-Beloeil, QC, in 2009 ranged from 14.6 to 18.9 mg SDG per gram of seed. Flax hulls produced in Winchester, ON, in 2010 were very rich in lignan; their SDG content was 40.0 mg/g of flax hull. Sesame seeds contained 0.18–1.89 mg SECO (aglycone of SDG) per gram of seed, with significant differences among black, white and brown sesame seed. Chia seeds contained 0.99–1.29 mg SECO per gram of seed, with significant differences among batches of seeds. Sunflower seeds had 0.046 mg SECO per gram of sample and almonds had 0.029 mg SDG per gram of sample. The optimized and evaluated MAE method is recommended for the general analytical quantification of lignans in plant samples.     

Optimization of Hull‐Less Pumpkin Seed Roasting Conditions Using Response Surface Methodology

Abstract: Response surface methodology (RSM) was applied to optimize hull‐less pumpkin seed roasting conditions before seed pressing to maximize the biochemical composition and antioxidant capacity of the virgin pumpkin oils obtained using a hydraulic press. Hull‐less pumpkin seeds were roasted for various lengths of time (30 to 70 min) at various roasting temperatures (90 to 130 °C), resulting in 9 different oil samples, while the responses were phospholipids content, total phenols content, α‐ and γ‐tocopherols, and antioxidative activity [by 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) free‐radical assay]. Mathematical models have shown that roasting conditions influenced all dependent variables at P < 0.05. The higher roasting temperatures had a significant effect (P < 0.05) on phospholipids, phenols, and α‐tocopherols contents, while longer roasting time had a significant effect (P < 0.05) on γ‐tocopherol content and antioxidant capacity, among the samples prepared under different roasting conditions. The optimum conditions for roasting the hull‐less pumpkin seeds were 120 °C for duration of 49 min, which resulted in these oil concentrations: phospholipids 0.29%, total phenols 23.06 mg/kg, α‐tocopherol 5.74 mg/100 g, γ‐tocopherol 24.41 mg/100 g, and an antioxidative activity (EC₅₀) of 27.18 mg oil/mg DPPH. Practical Application: A well‐defined roasting process is very important for the food industry to be able to produce pumpkin seed oil with desirable nutritive and chemical characteristics of this unique salad oil, which changes during the roasting. This study contributes to the knowledge of a product design process for the roasting conditions of naked pumpkin seeds based on results that have demonstrated that an increase in roasting temperature significantly increased the biochemical values and antioxidant properties of the obtained virgin oils.     

Effects of sesamol, sesamin, and sesamolin extracted from roasted sesame oil on the thermal oxidation of methyl linoleate

This study investigated the effects of lignan compounds extracted from roasted sesame oil, which were sesamol, sesamin, and sesamolin, on oxidation of methyl linoleate (ML) during heating. These compounds were added at 500 or 1000 mg/kg to ML, and α-tocopherol was used as a reference antioxidant. The ML added with lignans or α-tocopherol was heated at 180 °C for 60 min. Thermal oxidation of ML was evaluated by conjugated dienoic acid (CDA) contents, p-anisidine value (PAV), and ML retention. Contents changes of lignan compounds or α-tocopherol in ML during heating were monitored by high-performance liquid chromatography. CDA contents and PAV of samples increased and ML decreased with heating time at 180 °C. Samples added with lignan compounds showed lower CDA contents and PAV but higher ML retention than samples without lignan compounds. The antioxidant activity of sesame oil lignan compounds in ML oxidation during heating tended to be higher than that of α-tocopherol. The contents of lignan compounds in samples decreased with heating time due to their degradation, but the degradation rates were lower than that of α-tocopherol. This study suggested that sesame oil lignan compounds be used as antioxidants in oil at high temperatures for deep-fat frying due to their higher effectiveness and stability than α-tocopherol.