Effects of Fermented Edible Seeds and Their Products on Human Health: Bioactive Components and Bioactivities

There is a long history of using fermentation in food production. Edible seeds, such as certain beans and cereal grains, are important in the human diet and provide many health benefits. Various microbes, such as lactic acid bacteria, molds, and yeasts, considered as generally recognized as safe (GRAS) microbes, are commonly used to ferment edible seeds and their products. Fermentation can change bioactive components and produce new bioactivities. In order to highlight the importance of fermentation on bioactive components and bioactivities in edible seeds, this review, therefore, summarizes recent relevant studies and discusses fermentation procedures and influences of fermentation on their bioactive components and bioactivities. Overall, fermented edible seeds and their products contain enhanced bioactive components, especially γ‐aminobutyric acid and natural phenolics, and they possess versatile bioactivities, such as antioxidant and anti‐cancer effects, and, therefore, can be recommended as an important part of the human diet, or they can be developed into functional foods to help in the prevention of certain chronic diseases.     

乳酸菌发酵对龙眼果浆中糖和酚类物质的影响

本文研究了乳酸菌发酵对龙眼果浆糖类、酚类和黄酮类物质以及单体酚的影响。结果表明,龙眼果浆经乳酸菌发酵后,总糖和还原糖含量分别下降了48.59%和38.42%(p0.05)。龙眼果浆的总酚和总黄酮含量在发酵过程中均呈先下降后上升趋势,发酵后总酚含量为47.8 mg GAE/100 g,与未发酵前相比无显著性差异(p0.05),而发酵后总黄酮含量为13.7 mg CE/100 g,较未发酵前提高28.0%,差异显著(p0.05)。乳酸菌发酵显著增加了龙眼果浆中没食子酸、阿魏酸和槲皮素的游离态含量,其结合态含量显著下降,同时,原儿茶酸和芦丁的含量显著增加且只以游离态形式存在,结合态香草酸的含量显著降低。以上结果表明乳酸菌发酵可以显著降低龙眼果浆中的总糖和还原糖含量,提高其总黄酮含量,同时还提高了没食子酸、阿魏酸、槲皮素、原儿茶酸和芦丁等游离态单体酚的含量。该研究可以为龙眼果浆乳酸菌产品的研发提供指导。     

Bioactive Components and Antioxidant Capacity of Fruits from Nine Sorbus Genotypes

In this study, biochemical profile of fruits of 9 Sorbus genotypes was analyzed. The content of total sugars ranged from 69.7 g/kg (‘Titan’) to 217.5 g/kg (Sorbus torminalis) and total organic acids from 17.7 g/kg (‘Businka’) to 40.2 g/kg (S. torminalis). The highest content of total anthocyanins had ‘Burka’ (871 mg/kg FW) and ‘Businka’ (856 mg/kg FW). Quercetin derivatives represented more than 95% of total flavonols. ‘Alaja krupnaja’ had 3.5‐ to 29‐fold higher rutin content than other analyzed genotypes. S. torminalis fruits had the greatest diversity of isorhamnetin and kaempferol derivatives. Chlorogenic acid was the major hydroxycinnamic acid and its share was 33% to 73% of total analyzed hydoxycinnamic acid derivatives. The richest in chlorogenic acid were ‘Krasavica’ and ‘Alaja krupnaja’ fruits. Cultivar ‘Businka’ had the highest content of epicatechin (40.7 mg/kg) and neochlorogenic acid (1061 mg/kg). Different procyanidin oligomers were detected among flavanols in Sorbus fruits. The highest content of total flavanols was measured in ‘Alaja Krupnaja’ fruits. Cultivars ‘Krasavica’ (84.5 mg/kg) and ‘Burka’ (85.1 mg/kg) had 1.2‐ to 6.9‐fold higher amount of total carotenoids. ‘Businka’ was highlighted as the richest in total tannin and phenolic contents (3768 mg GAE/kg) and consequently, it had the highest antioxidant activity (57.6 mM TE/kg FW). Being abundant in polyphenolics, some extracts of Sorbus genotypes, for example, ‘Businka,’ ‘Burka,’ and ‘Alaja krupnaja’ could serve as valuable resource of bioactive compounds to food and pharmaceutical industries.     

四种豆类中多酚、类黄酮含量及抗氧化活性研究

对豇豆、红小豆、绿豆和蚕豆4种豆类中游离态和结合态的多酚及类黄酮的含量进行测定,并比较了其体外抗氧化活性。数据表明,4种不同豆类的游离态多酚和结合态多酚含量范围分别为1.35～1.75 mg/g和8.63～10.11 mg/g;游离态类黄酮和结合态类黄酮含量范围分别为1.58～2.07 mg/g和3.92～5.08 mg/g;其中结合态多酚含量是游离态多酚的5倍以上,结合态类黄酮含量是游离态的2倍以上。4种豆类游离态和结合态提取物均具有良好的抗氧化活性,其中游离态提取物对DPPH自由基的清除能力明显高于结合态,而结合态对FRAP、ABTS、O2-自由基的清除能力明显高于游离态。豆类中含有丰富的酚类、类黄酮等物质,并且主要以结合态形式存在,具有较强的抗氧化活性。     

酶解水溶剂法提取莜麦多酚的工艺研究

莜麦是内蒙地区特色作物之一,具有降血糖、降血脂等生理功能。为了研究莜麦中多酚的提取,以内蒙古莜麦为原料,以多酚得率为依据,在单因素试验的基础上,通过正交试验对酶解水溶剂法提取酚类物质的工艺进行优化,得出最佳提取工艺为:复合酶用量0.8%,酶解时间80 min,酶解温度55℃,pH值5.0,此时酚类物质的得率为:2.950 mg/g。在此基础上与微波辅助有机溶剂提取法比较,得出酶法提取多酚得率显著高于微波辅助提取法。表明:在提取莜麦多酚方面,酶解水溶剂提取法优于微波辅助有机溶剂提取法。     

蓝莓花、茎、叶酚类物质含量及抗氧化活性比较

比较蓝莓花、嫩茎、嫩叶及老叶总多酚、总黄酮、原花青素的含量,并研究其抗氧化性能差异。结果表明:嫩叶中总多酚含量最高,为43.77 mg GAE/g(以干质量计,下同),分别是花、嫩茎和老叶的3.45、1.42、1.12倍;老叶中总黄酮、原花青素含量最高,为68.01 mg RE/g、23.29 mg CAE/g,分别是花的2.57倍和4.61倍、嫩茎的1.79倍和1.23倍、嫩叶的1.03倍和1.98倍。抗氧化性能中,老叶的铁还原能力最大,其次是嫩茎和花,嫩叶较差;清除·OH的能力为嫩茎嫩叶花老叶;清除DPPH自由基能力和总抗氧化能力均为嫩茎嫩叶老叶花甲醇提取物,均高于对照品;蓝莓各部分提取物对DPPH自由基的清除能力最强,总抗氧化能力次之,清除·OH能力和铁还原能力较差。     

大花罗布麻不同部位酚类物质含量及其抗氧化活性比较研究

目的：比较大花罗布麻根、茎、叶、花4 个部位中游离态和结合态酚类物质的含量和抗氧化活性的差异,并分析含量与抗氧化活性之间的相关性。方法：采用Folin-Ciocalteu法、NaNO2-Al(NO3)3法分析罗布麻的根、茎、叶、花4 个部位的游离态和结合态总多酚、总黄酮含量,采用DPPH自由基清除能力、ABTS+·清除能力和铁离子还原能力3 种方法评价其体外抗氧化能力差异。结果：大花罗布麻总酚含量次序为：叶＞根＞花＞茎,各样品间存在显著性差异（P＜0.05）。各部位游离酚、结合酚和总多酚含量分别介于3 560.19～6 273.23、13.45～22.01和3 582.2～6 286.68 mg GAE/100 g干质量,其游离态多酚占总酚含量百分比平均为99.60%;游离态黄酮、结合态黄酮和总黄酮含量分别介于1 080.30～2 488.21、9.69～28.59、1 106.81～2 516.80 mg RE/100 g 干质量,其游离态黄酮占总黄酮含量的百分比平均为98.64%。大花罗布麻叶提取物清除DPPH 自由基、ABTS+·能力和总还原力最强,抗氧化活性与总酚含量之间具有良好的线性关系（r＞0.950 0）。结论：大花罗布麻各部位中含有较丰富的酚类物质,具有较强的抗氧化活性。     

重庆地方名柚果肉酚类物质含量及其抗氧化活性分析

通过紫外分光光度计法和高效液相色谱法分别测定10 种重庆地方名柚成熟果实囊衣、汁胞2 个部位的总酚、总黄酮含量及类黄酮、酚酸组分和含量,并采用1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-picrylhydrazyl,DPPH）、铁离子还原能力（ferric reducing antioxidant power,FRAP）测定、2,2’-联氮-双-（3-乙基苯并噻唑啉-6-磺酸）二铵盐（2,2’-azinobis-(3-ethylbenzthiazoline-6-sulphonate),ABTS）3 种方法对其抗氧化活性进行评价。结果表明：囊衣的总黄酮含量和类黄酮含量较高,‘琯溪蜜柚’总黄酮含量最高达10.97 mg/g,类黄酮中地奥司明含量最高,均值为1 000.72 μg/g,其含量最高为‘五布柚’,达到2 366.77 μg/g;汁胞的总酚含量和酚酸含量较高,‘真龙柚3号’总酚含量最高达8.84 mg/g,酚酸中没食子酸含量最高,均值为1 040.16 μg/g,其含量最高为‘长寿沙田柚’,达到1 325.89 μg/g。利用DPPH法和FRAP法测定2 个部位抗氧化活性,汁胞高于囊衣,ABTS法则囊衣高于汁胞。综合抗氧化能力指数表明,‘琯溪蜜柚’囊衣、‘梁平柚78-8’汁胞的抗氧化活性最强。通过本研究,不仅能够了解重庆地方名柚果实囊衣、汁胞部位酚类物质组分和含量,同时为柑橘酚类物质的应用选择提供了一定的理论依据,促进了柑橘果品营养学的发展。     

蛋白质和酚类的浓度及其比率对其聚合物浊度的影响

本实验采用明胶和单宁酸、麦醇溶蛋白和儿茶素分别组成两个模拟体系,研究其蛋白质和酚类的浓度及其比率对聚合物浊度的影响。蛋白质和酚类聚合,与蛋白质和酚浓度及其比率有关;随蛋白质和酚类浓度的增加,其聚合后的浊度也增加,并且变化趋势是固定蛋白质或多酚的浓度,随多酚或蛋白质浓度的增加,浊度增加,增加到最大值后又下降;单宁酸和明胶在pH3.7的0.02mol/L的磷酸盐缓冲溶液中,25℃条件下聚合30min,当明胶与单宁酸浓度比为1:1、1:4时,形成的聚合物浊度最大。     

Glycine Protects Against Strong Protein-Denaturing Activity of Oleuropein, a Phenolic Compound in Privet Leaves

In previous studies, we reported the existence of a high concentration of free glycine in the digestive juice of several Lepidoptera larvae, particularly in the digestive juice of species that feed on the privet tree, Ligustrum oblusifolium. The water extract of privet leaves showed very strong protein-denaturing activity and lysine-decreasing activity, which closely resembled activity of oxidized polyphenolics. Addition of 1% glycine to the extract could completely inhibit these activities. Free glycine may be secreted into the digestive juice by larvae as an adaptive mechanism for chemical defense against its host plants. The protein-denaturing compound in privet leaves is present in the cytosol or in the vacuoles of the leaf cells. The compound does not show protein-denaturing activity without oxidation, but when mixed with intact organelles under low osmotic conditions to give an osmotic shock, a very high protein-denaturing activity is produced. Our results suggest that the privet tree is endowed with a defense mechanism in which a stable compound in the cytosol or in the vacuoles is activated into a chemically active denaturant by an enzyme present in the organelles (including chloroplasts) after the leaves are eaten by insects and the organelles are broken by osmotic shock or by digestive mechanisms. Based upon HPLC and NMR data, we conclude that the denaturing compound is oleuropein, an o-dihydroxyphenolic compound. This compound makes up 3% of the wet weight of privet leaves. The protein-denaturing activity of purified oleuropein activated by the leaf enzyme is high enough to account for all the denaturing activity in a water extract of privet leaves. The denaturing reaction is completely inhibited by free glycine. Our results suggest that the protein-denaturing activity and lysine-decreasing activity of privet leaves are caused by oxidized polyphenolics, and that some insects secrete free glycine to counter the denaturing activity of oxidized phenolics. The chemical mechanism of counteraction by glycine is also considered. Free glycine in the midgut of insects probably protects proteins from denaturation by competing with proteins for oxidized phenolics.