超临界流体萃取与二乙醇胺法综合制备米糠油

以市购米糠为原料,采用超临界流体萃取法提取米糠油,并对毛糠油的简化精炼工艺进行研究。原料经微波预处理降低解脂酶活性后,利用超临界CO2分段萃取,先后控制条件15MPa、32℃、1.0h和35MPa、40℃、4.0h获得毛糠油Ⅰ、Ⅱ。用二乙醇胺处理毛糠油Ⅱ,通过单因素实验和正交实验得出二乙醇胺法精炼毛糠油的最佳条件为:二乙醇胺加入量为油重的9%,精炼温度为50℃,振荡时间为15min。在此条件下精炼毛糠油,油脂酸价可降至0.85mgKOH/g,酸价降低率达到94.33%。超临界流体萃取与二乙醇胺法精炼综合处理所得米糠油清澈、透明,谷维素含量为1.73%,色度达到了国家标准。     

鼠尾草提取物多酚含量与抗氧化活性的研究

研究从不同的角度来评价鼠尾草提取物的抗氧化活性。采用50%丙酮和70%乙醇两种溶剂对鼠尾草进行提取,用Folin-Ciocalteu法测定提取物中的多酚含量,并用四种方法,即清除DPPH（1,1-二苯基-2-三硝基苯肼）自由基法、螯合Fe2+法、还原力法和磷钼络合物法测定提取物的抗氧化活性。研究结果表明,50%丙酮提取物中的多酚含量显著高于70%乙醇提取物。鼠尾草提取物具有良好的自由基清除能力、螯合Fe2+能力、还原能力和总抗氧化能力。鼠尾草50%丙酮提取物的抗氧化活性总体上比70%乙醇提取物高（还原力除外）。      

高效液相色谱测定广西生鲜乳中的维生素A

为了建立生鲜乳中维生素A的一种快速、准确、灵敏度高的检测方法,样品经皂化后,经石油醚提取,浓缩后采用高效液相色谱法,以Shim-pack VP-ODS柱(4.6 mm×150 mm,5μm),柱温35℃,检测波长325 nm,流动相为甲醇∶水(98∶2,体积比),流速1.0 mL/min的条件进行实验。结果维生素A在0.174～87.2μg/mL范围内线性关系良好,相关系数r=0.9999,平均回收率为98.17%,RSD=1.90%。建立的方法准确、可靠,可以用于生鲜乳中维生素A的含量检测。     

透性化处理对嗜酸乳杆菌细胞亚油酸异构酶表观活力的影响

来源嗜酸乳杆菌的亚油酸异构酶是胞内酶,完整的细胞呈现较低的酶活。研究了乙醇、乙醚、甲苯、溴化十六烷三甲基铵(CTAB)等透性剂对嗜酸乳杆菌细胞亚油酸异构酶活力的影响。结果表明,经过透性化处理的细胞亚油酸异构酶活力显著提高,其中最好的透性剂为CTAB。当CTAB的浓度为1%,30℃保温20～30min,酶活高达405.6U/g,是超声波破碎的细胞表观酶活的5.4倍。透性化细胞中亚油酸异构酶热稳定性提高,60℃保温2h,残余酶活为80%。透性化细胞生物转化共轭亚油酸转化率达84.5%,用透性化细胞可有效转化亚油酸为共轭亚油酸。     

Capsular and slime-polysaccharide production by Lactobacillus rhamnosus JAAS8 isolated from Chinese sauerkraut: Potential application in fermented milk products

Exopolysaccharides (EPSs) produced by lactic acid bacteria (LAB) play an important role in the improvement of the physical properties of fermented dairy products. To find EPS-producing LAB strains with potential industrial applications, a Lactobacillus rhamnosus strain, L. rhamnosus JAAS8, that is capable of producing two forms of EPS when grown in MRS broth or semi-defined medium with glucose as a carbon source was isolated and identified from Chinese sauerkraut. The capsular-polysaccharide (CPS) present surrounding the bacterial surface of L. rhamnosus JAAS8 was observed by both optical microscopy and transmission electron microscopy. The slime-polysaccharide (SPS) present in the growth medium was produced mainly during the exponential growth phase, while the CPS was produced only in fermentation. Monosaccharide analysis of the purified polysaccharide samples showed that the CPS was composed of galactose and N-acetylglucosamine in a molar ratio of 5:1, and the SPS was composed of galactose, glucose and N-acetylglucosamine in a molar ratio of 4:1:1. The use of L. rhamnosus JAAS8 could be considered for potential applications in the dairy industry to improve the rheological properties of fermented milk products by increasing their water-holding capacity and viscosity.     

Non‐digestible carbohydrates in Brazilian soybean seeds [Glycine max (L.) Merril]

Non‐digestible carbohydrate fraction (NDCF) consists of a range of bioactive compounds that escape digestion in the small intestine. NDCF is mainly composed of dietary fibre (DF) and non‐digestible oligosaccharides (NDO). The objective of this work was to analyse directly and compare the NDCF in two Brazilian cultivars of soybean seed with commercial flour. Brazil is the second major soybean producer in the world. The seed cultivars showed on average a NDCF value of 32.80 g per 100 g dry weight (dw). Regarding DF, insoluble DF (IDF) was the main fraction amounting on average to 98%. Uronic acids were significantly higher than neutral sugar (NS) in IDF and soluble DF (SDF) fractions. There was a considerable amount of Klason lignin – on average 84.14% of DF. Regarding NS profile, mannose was the most important sugar in SDF, whereas galactose and arabinose were predominant in IDF. Stachyose was the main oligosaccharide in NDO. DF and NDO were in the same proportion (94.2:5.8) in tested cultivars. No differences in swelling, water retention, or oil retention capacities between seed cultivars were detected. This study on non‐digestible carbohydrate components in soybean seed gives a different approach to the current nutritional knowledge on protein and oil constituents.     

Influence of the degree of fusariosis on technological traits of wheat grain

The paper aims to enlarge the current knowledge about the dependence of technological traits of wheat grain on its degree of infestation (DI) with fusariosis. Samples of grain of four wheat cultivars were obtained from naturally grown crops (control) and from crops inoculated with Fusarium culmorum from which three degrees of kernel infestation were selected. Samples were determined for thousand kernels weight (TKW), total protein, starch and wet gluten (WG) contents, Hagberg falling number (HFN) and sedimentation value (SV). Content of protein and wet gluten showed higher values for moderately infested kernels (up to 15 and 25%, respectively, when compared to control grain) than for kernels lightly or heavily infested. All the remaining traits had values lower than that for control grain and showed a decrease with increasing DI. Decrease for the heaviest infestation was on average: 8, 29, 31 and 34% for starch, TKW, HFN and SV, respectively.     

44dtex/36f锦纶6细旦多孔FDY生产工艺

分析工艺参数如纺丝温度、冷却条件、热辊温度和拉伸倍数等对锦纶6细旦FDY生产的影响,对44 dtex/36 f锦纶6细旦FDY的生产工艺进行研究,在生产中选择纺丝温度248-262℃,侧吹风温度17℃,风速0.35 m/s,纺丝张力控制在10-11 cN范围,卷绕速度4 300 m/min,能生产出品质优良的产品。     

Utilisation possibility of Enterococcus faecalis isolates from neonate's faeces for production of fermented sausages as starter cultures

This study aimed at assessing the utilisation possibility of Enterococcus faecalis as starter cultures for production of fermented sausages. The E. faecalis isolates isolated from faeces samples of 5‐day‐old healthy newborn babies, identified by 16SrDNA sequencing and free from virulence determinants as proven by genomic sequencing, were used for fermented sausages production as starter culture. Six treatments (four inoculated with four different E. faecalis isolates, one with commercial starter culture and one control) were prepared. The inoculation with E. faecalis showed a stronger acidification compared with the control. The treatments with E. faecalis showed significantly higher flavour and acceptability scores in comparison with the control or commercial starter culture. Both of commercial starter culture and E. faecalis were positive with tyramine. Apart from the amine production, the inoculation with E. faecalis generally improved the acidifying activity and flavour of the products, suggesting their application potentials in fermented sausages production as starter cultures.     

Stability of antioxidant peptides from duck meat after post‐mortem ageing

The stability of antioxidant peptides from aged duck meat during processing and simulated gastrointestinal digestion was investigated. The antioxidant peptides preserved a high stability in the presence of diverse NaCl or upon various time heating. The antioxidant activities were strengthened by the addition of 4–8% glucose or by heating at 100 °C, whereas they were lost under alkaline conditions. During in vitro digestion, the antioxidant activities increased with pepsin treatment but then decreased following trypsin digestion. Pepsin hydrolysed peptides into short fragments and results in the increased exposure of internal hydrophobic amino acids. With further treatment by trypsin, peptides can be hydrolysed completely and more free amino acids were released, leading to the decline in surface hydrophobicity. These variations might be responsible for the change in antioxidant activity during in vitro digestion. The antioxidant peptides from aged duck with high stability can be used as functional food ingredients to improve human health.