不同发酵法对油菜蜂花粉破壁的影响

采用自然发酵法、干性酵母直接发酵法、酵母发酵-酶解法对油菜蜂花粉进行破壁,比较3种破壁方法的破壁率、破壁花粉营养成分可溶性糖、游离氨基酸、总黄酮、维生素C及风味改善,从而筛选出最佳的破壁方法.结果表明,采用干性酵母直接发酵法、酵母发酵-酶解法得到的破壁率、营养成分及风味改善优于自然发酵法,从经济方面来考虑酵母发酵法为油菜蜂花粉的最佳破壁法.     

Determination and distribution of biogenic amines in bee pollen

The natural decomposition of proteins yields peptides and amino acids, which are susceptible to further decay, resulting in formation of biogenic amines (BAs) in proteinaceous foods such as bee pollen (BP). However, excessive consumption of BAs will bring side effects, so it is vital to study the presence of BAs in BP. In this study, a sensitive and reliable ultra ‐ high‐performance liquid chromatography–tandem mass spectrometric method was used for the determination of 12 BAs in BP. Large variations in the distribution and levels of BAs were observed with its total concentrations ranging from 6837.4 to 25444.2 μg kg^?1. In addition, the changes in the levels of BAs during storage and fermentation were preliminarily investigated. The results showed that fermentation significantly altered the quantities of BAs in rape BP, while changes during storage were modest. The results of this study could be applied for quality evaluation and risk assessment of BP in near future.     

油菜花粉和茶花花粉中重金属含量的分布特征研究

目的 考察油菜花粉和茶花花粉中7种重金属(类金属)元素含量的分布特征.方法 采用微波消解-电感耦合等离子体质谱法对所采集的蜂花粉样品中铬、锰、砷、铜、镍、镉和铅7种元素含量进行分析测定,通过统计分析考察油菜花粉和茶花花粉中各元素含量是否有显著性差异.结果 油菜花粉和茶花花粉均存在重金属污染问题,但重金属污染水平存在差异...     

蜂粮的营养成分和微生物发酵过程研究进展

蜂粮是蜜蜂蜂群中大幼虫、工蜂和雄性蜂的主要食物来源,也是蜂群生存、发展和繁殖的营养保证。目前由于天然蜂粮生产成本较高,而人工蜂粮生产技术中各阶段的发酵条件尚未明确,蜜蜂利用蜂花粉酿制蜂粮的全过程尚无法完全模拟,导致蜂粮的开发利用仍存在一定的技术难题。该文针对蜂粮的营养成分、发酵过程、微生物组成及研究现状等进行了综述,以期为蜂粮产品的研发和生物学功能研究提供理论参考。     

Analysis of coenzyme Q10 in bee pollen using online cleanup by accelerated solvent extraction and high performance liquid chromatography

A method for the determination of coenzyme Q10 in bee pollen has been developed applying an online cleanup of accelerated solvent extraction and using environmentally acceptable organic solvents. The extracted samples were analysed by high performance liquid chromatography with diode array detection. The optimised method employed 10 mL extraction cells, 1 g sample size, absolute ethanol as extraction solvent, 80 °C of extraction temperature, one extraction cycle, 5 min of static time, Cleanert Alumina-N as sorbent and 60% flush volume. The method was validated by means of an evaluation of the matrix effects, linearity, limit of detection (LOD) and quantification (LOQ), trueness, precision and stability. The assay was linear over the concentration range of 0.25–200 mg/L and the LOD and LOQ were 0.16 and 0.35 mg/kg, respectively. The recoveries were above 90%. The inter- and intra-day precision was below 6.3%. The method has been successfully applied to the analysis of bee pollen samples. For 20 bee pollen products, the coenzyme Q10 content varied from not detectable to 192.8 mg/kg.     

Chemical composition and nutritional attributes of selected newly developed lines of soybean (Glycine max (L) Merr)

The chemical composition and nutritional properties of raw, autoclaved and boiled samples of three promising advanced breeding lines of soybean (TG_x 923 ? 2^EN, TG_x 1019 ? 2^EN and TG_x 1497 ? 1^D), part of a larger collection evaluated in agronomic field trials in Nigeria, were investigated. Protein quality was evaluated using weanling albino rats fed diets which were formulated to supply 10% protein using soybean samples, with casein as a control. Raw seeds contained 35.6–42.4% crude protein, 8.9–9.8 mg iron per 100 g, 8.62–18.21 mg trypsin inhibitor g^?1 and 2.25–6.15 mg phytic acid g^?1 seed flour. TG_x 923 ? 2^EN possessed higher crude protein contents and lower amounts of trypsin inhibitor, polyphenol and phytic acid compared with TG_x 1019 ? 2^EN or TG_x 1497 ? 1^D. Boiling proved more effective than autoclaving for reducing the levels of antinutrients and improving the protein quality of the beans, as shown by the higher values for weight gain, protein efficiency ratio (PER), net protein ratio (NPR) and true digestibility (TD) of boiled samples. There were no significant (p > 0.05) differences between the values obtained for PER, NPR and TD of diets containing boiled samples of TG_x 923 ? 2^EN and casein, indicating the nutritional superiority of this soybean line compared with TG_x 1019 ? 2^EN and TG_x 1497 ? 1^D. © 2002 Society of Chemical Industry     

不同产区青海玉树芜菁中营养成分分析与比较

目的:为全面了解青海玉树芜菁的食用价值,选取青海玉树4个不同产区共12批芜菁,对其营养成分进行分析评价和比较,为芜菁再加工产品的开发和利用提供重要依据。方法:分别用亚临界流体丁烷和1,1,1,2-四氟乙烷(R134a)萃取出芜菁中的β-谷甾醇和总黄酮,然后分别测定了芜菁β-谷甾醇和总黄酮含量,同时还测定了芜菁多糖、可溶性糖、总皂苷、氨基酸、蛋白质及各种矿物质元素含量等。采用SPSS 19.0对玉树4个不同产区芜菁中各营养成分含量进行多重比较。结果:曲麻莱县芜菁中蛋白质(2.20%)、总氨基酸(15.35%,以干计)和总皂苷(0.35%)含量最高,称多县芜菁中总糖含量最高(2.90%),囊谦县芜菁中粗纤维(1.01%)和总矿物质元素(447.5 mg/100 g)含量最高。结论:青海玉树芜菁营养价值高,具有良好的食用价值和开发前景,可为青海玉树芜菁的质量控制提供依据。     

新疆芜菁不同品种营养成分分析与比较

为全面了解新疆芜菁的食用价值,选取了新疆芜菁主产区的13个芜菁品种,对其营养成分进行分析评价,为充分开发与利用新疆芜菁资源,提高新疆芜菁产品的附加值提供依据。本实验运用高效液相色谱法(High Performance Liquid Chromatography,HPLC)、原子吸收分光光度法(Atomic Absorption Spectrophotometer,AAS)测定了13种新疆芜菁中所含氨基酸、蛋白质、钙、镁等矿质元素含量。结果表明:在参试品种中,绿昆芜菁的总氨基酸含量、蛋白质、总矿物质含量均最高,分别为12.32%、2.33%、57488 mg/kg。结论:绿昆芜菁具有高氨基酸、高矿质元素、高蛋白、低酸等优良品质,适宜作为优质栽培品种,其次为柯坪芜菁和亚华芜菁。不同品种新疆芜菁营养成分含量较高,蛋白质及矿物质元素含量丰富,营养价值高,具有良好的食用价值和开发前景。      

Effect of debittering and solid-state fermentation processes on the nutritional content of lupine (Lupinus mutabilis Sweet)

There is a growing interest in vegetable-based sources of proteins. Despite its high nutrient content, lupine has been rarely exploited as a protein source due to the presence of high levels of non-nutritive compounds such as alkaloids, which impart a bitter taste. Here, we evaluated the effect of debittering and solid-state fermentation on the nutritional contents of three lupine varieties (Lupinus mutabilis Sweet). These processes induced significant changes (P < 0.05) in the nutritional composition of the three lupine varieties (INIAP-450, INIAP-451 and Criollo) and increased the protein levels to 644.55 g kg⁻¹ (Criollo variety) and the levels of several constituent amino acids such as valine (54.62 g kg⁻¹), methionine (42.47 g kg⁻¹), isoleucine (59.27 g kg⁻¹) and leucine (76.32 g kg⁻¹). The ether extract of INIAP-450 showed increased levels (up to 244.03 g kg⁻¹); especially, monounsaturated fatty acids (559.78 g kg⁻¹) and polyunsaturated fatty acids (293.17 g kg⁻¹) were observed. The omega-6/omega-3 ratio in the debittered grain oil reached the minimum requirement established for good-quality oils (5/1). However, the levels of other components decreased, showing levels up to 13.04 g kg⁻¹ (total starch) in the Criollo variety, 22.62 g kg⁻¹ (resistant starch) in INIAP-450, 6.53 g kg⁻¹ (potassium) in INIAP-451, 46 g kg⁻¹ (iron) in INIAP-451 and 29.75 g kg⁻¹ (zinc) in INIAP-450.     

Fatty acids and triacylglycerols in the seed oils of Saudi Arabian date (Phoenix dactylifera L.) palms

Total lipids, fatty acids and triacylglycerols in seeds of the four Saudi Arabian date cultivars ‘Anbra’, ‘Megadwel’, ‘Sacai’ and ‘Sfwai’ were analysed. Total lipid contents ranged between 7.3 and 8.6%. Oleic, lauric and myristic acid represented the most abundant fatty acids in date seed oil. HPLC-DAD-ESI-MSⁿ analysis enabled the identification of 40 triacylglycerols with equivalent carbon number (ECN) 36–54, of which 17 were detected for the first time. Triacylglycerols mainly comprised LaOL, LaLaL, LaML, MML/LaPL and LaOO. ‘Anbra’ oil was characterised by highest proportions of saturated fatty acids and triacylglycerols with ECN 36 and 48–54. Unsaturated fatty acids prevailed in the three remaining varieties. Elevated proportions of triacylglycerols with medium ECNs were found in ‘Megadwel’ and ‘Sfwai’ oils. Aside from highest total lipid contents, ‘Sacai’ seeds predominantly contained triacylglycerols with low ECNs. Multivariate statistical analyses elucidated varietal influences on the fatty acid and triacylglycerol composition of date seed oil.     

不同产地山茱萸氨基酸含量分析及其营养价值评价

目的 分析全国29个产地山茱萸的氨基酸成分,评价其营养价值。方法 采用氨基酸自动分析仪测定山茱萸样品中氨基酸的含量,通过氨基酸比值系数法对其营养价值进行评价,并对所得数据进行相关性分析、主成分分析和聚类分析。结果 不同地区山茱萸样品的氨基酸总量存在差异,在15.12～26.47 mg/g之间;山茱萸中的氨基酸种类丰富,29份样品中均检测到17种氨基酸,其中包含7种必需氨基酸,占总氨基酸含量的35.75%,接近联合国粮农组织和世界卫生组织模式标准;含量最高的3种氨基酸依次为天冬氨酸、谷氨酸和亮氨酸,均为药效氨基酸;药效氨基酸占总氨基酸含量的60.02%～68.48%;山茱萸中氨基酸组成比例合理,限制氨基酸为甲硫氨酸和半胱氨酸,氨基酸比值系数分值介于61.859～81.443之间;不同产地的山茱萸氨基酸组成相关性显著,主成分分析提出取3个主成分,累计方差贡献率为87.884%,系统聚类分析法将其归为4类,其中以陕西秦岭和河南伏牛山地区品质为佳。结论 山茱萸作为一种药食同源物质,氨基酸种类及含量丰富,综合开发利用的市场潜力巨大,本研究可为不同产地山茱萸的品质评价和资源开发提供参考。     

Progress and challenges in improving the nutritional quality of rice (Oryza sativa L.)

Rice is a staple food for more than 3 billion people in more than 100 countries of the world but ironically it is deficient in many bioavailable vitamins, minerals, essential amino- and fatty-acids and phytochemicals that prevent chronic diseases like type 2 diabetes, heart disease, cancers, and obesity. To enhance the nutritional and other quality aspects of rice, a better understanding of the regulation of the processes involved in the synthesis, uptake, transport, and metabolism of macro-(starch, seed storage protein and lipid) and micronutrients (vitamins, minerals and phytochemicals) is required. With the publication of high quality genomic sequence of rice, significant progress has been made in identification, isolation, and characterization of novel genes and their regulation for the nutritional and quality enhancement of rice. During the last decade, numerous efforts have been made to refine the nutritional and other quality traits either by using the traditional breeding with high through put technologies such as marker assisted selection and breeding, or by adopting the transgenic approach. A significant improvement in vitamins (A, folate, and E), mineral (iron), essential amino acid (lysine), and flavonoids levels has been achieved in the edible part of rice, i.e., endosperm (biofortification) to meet the daily dietary allowance. However, studies on bioavailability and allergenicity on biofortified rice are still required. Despite the numerous efforts, the commercialization of biofortified rice has not yet been achieved. The present review summarizes the progress and challenges of genetic engineering and/or metabolic engineering technologies to improve rice grain quality, and presents the future prospects in developing nutrient dense rice to save the everincreasing population, that depends solely on rice as the staple food, from widespread nutritional deficiencies.     

Simulated gastrointestinal digestion and in vitro colonic fermentation of date (Phoenix dactylifera L.) seed polyphenols

Date seeds are a by‐product of date fruit industry and a rich source of polyphenols. In this study, in vitro bioaccessibility and colonic fermentation of major polyphenols from date seed powder (DSP) and DSP‐fortified yoghurt (DSPY) were investigated using HPLC. Catechin, epicatechin and procyanidin A2, B1 and B2 were stable during simulated gastric and sequential intestinal digestion. Bioaccessibility was significantly (P < 0.05) higher for all compounds from DSPY compared with DSP. After in vitro colonic fermentation of insoluble digestion materials, most of the target compounds were metabolised by faecal bacteria to ferulic acid, 3‐hydroxyphenylacetic acid, 3‐phenylpropionic acid and 3‐(4‐hydroxyphenyl) propionic acid. DSPY contained significantly (P < 0.05) higher level of free polyphenols as indicated by higher bioaccessibility; however, the stability of the polyphenols and their fermentation products from DSPY were similar to that of DSP alone. These data would be useful in product developments incorporating DSP as a source of polyphenols in food products.     

Physicochemical,technological and sensory characteristics of a rice (Oryza sativa L.) and bean (Phaseolus vulgaris L.) soup prepared by extrusion

The aim of this work was to prepare and evaluate an instant soup formulated with broken rice and beans processed by thermoplastic extrusion using a pilot‐scale, single‐screw extruder. The final product was characterised regarding its physicochemical composition, amino acid profile, functional–technological properties and sensory performance. The extrusion parameters were set using three extrusion zone temperatures (30, 40 and 70 °C), a screw speed of 177 rpm, feed rate of 260 g min^?1. and circular matrix of 3.85 mm. The final product contained considerable levels of protein (12.91 g per 100 g) and dietary fibre (8.07 g per 100 g). Amino acid profile analysis showed that only sulphur‐containing amino acids and tryptophan were limiting with the remaining present in adequate concentrations to meet children's requirements. Regarding functional and technological properties, the instant soup powder showed appropriate water solubility and water absorption indexes as expected. The soup sensory analysis indicated good acceptability, with a purchase intent index of 71%.