添加丢糟生产酱油大曲的效果研究

通过对添加曲酒丢糟生产酱油大曲的效果研究,并对影响成曲质量和酱油品质的工艺条件(培曲时间、温度)进行了探讨。比较了改良曲与传统曲的性能优势及所产酱油的质量指标差异,确定了丢糟的最佳加入量为10%,培曲的时间24h,最适温度33℃。     

A probabilistic approach to determine thermal process setting parameters: application for commercial sterility of products

The objective of the probabilistic data analysis presented in this paper was to enable the thermal process to be set on actual data rather than on generic or conservative rules. The application was an ambient stable soup product, heated in a continuous UHT line. The data set comes from a decade of microbiological analysis: initial spore load and survival spore concentration after moderate heat-treatment (100 °C for 15 min and 110 °C for 15 min) have been enumerated in forty eight ingredients. The probabilistic analysis was carried out within a risk-based context, considering a Performance Objective, PO, set after the heat-treatment process and an initial spore contamination (H₀) at the ingredient mixing step. The probabilistic analysis was based upon Bayesian inference, chosen for its flexibility when dealing with censored data (some values were reported as less than 1 log cfu/g) and also for its ability to incorporate in the data analysis prior information. Beforehand, Z values around 10 °C for aerobic bacterial spores, and log count error around 1 log, were assumed. The methodology and the results are reported using two ingredients (garlic and milk powder) illustrating the ‘not detected’ (censored data) issue and also the inter-ingredient variability. Indeed, Z was estimated to be 13.6 °C (mean) for spores selected from garlic and 5.9 °C for those selected from milk powder. Based upon a hypothetical soup recipe with these two ingredients, the sterilization value was estimated to be 13 min (95th percentile). The potential use of similar methodology to design and set the sterilization value for the thermal process of future products, is discussed.     

Changes in lipid content and composition during germination of groundnuts

The cotyledons of two varieties of germinating groundnut seeds (Runner and Bunch) were analysed periodically for their lipid content and fatty acid composition over a period of 132 h. The lipid content decreased drastically during germination. More drastic changes in lipid constituents were observed for light-grown seedlings than for dark-grown ones. In general, the non-polar lipids (NPL) were metabolised faster than the polar ones (P > 0.05) especially in those seeds grown in the dark. The rate of decrease in NPL content almost paralleled that of increase in glycolipid (GL) content. Triacyl glycerol content decreased noticeably during germination while other NPL tended to increase. Among the GL, sterylglucoside increased rapidly during early germination under darkness, only to decrease steadily thereafter. A converse effect was observed for acyl sterylglucoside which, in the dark, decreased rapidly at early germination only to increase equally rapidly later on. Among the phospholipids (PL), only phosphatidic acid showed a marked increase during germination, under both growth conditions, while others tended to decrease in varying degrees. The changing patterns of GL and PL during germination seem to follow the pattern of the formation of photosynthetic tissues and the metabolic conversion of PL. The major fatty acids of the three lipid groups, which more or less decreased or increased in varying degrees with germination in light-grown seeds were oleic, linoleic, palmitic, stearic, arachidic and lignoceric acids in decreasing order of prominence at early germination.     

Effect of seed treatments on the chemical composition and properties of two amaranth species: starch and protein

The seeds of two Amaranth species were studied. The starch contents were 543 and 623 g kg^?1 while crude protein contents were 154 and 169 g kg^?1 for Amaranthus caudatus and Amaranthus cruentus seeds, respectively. The effect of several treatments, including cooking, popping and germination and flour air classification on the protein and starch properties were studied. Air classification decreased the starch content and increased the protein content, while heating increased the protein but did not affect the starch content. Germination decreased both starch and protein contents. Amylose content was increased by air classification and heating, but was not affected by germination. It was found that all treatments increased the starch swelling power and reduced the falling number. The resistant starch content was increased in the high protein flour (HPF) fraction and germinated flour compared with the raw flour, while its content decreased in the heat treated seed flours. These processes also affected the starch gelatinization temperature and peak viscosity. The thermal properties of the starch flour were not affected by air classification while gelatinization energy was decreased significantly (by 52.0 and 90.0% and by 70.0 and 95.0%) in cooked and popped A caudatus and A cruentus seed flours, respectively. The gelatinization energy was highest in germinated seeds dried at 90 °C with values of 2.67 and 3.87 J g^?1. Air classification reduced the level of all protein fractions. Thermal treatment decreased the water‐soluble fraction (albumins + globulins) and alcohol‐soluble fraction (prolamins) in both species. The levels of all fractions except the water‐soluble fraction (albumins + globulins) were reduced significantly in both species by germination, which mainly increased the amount of aspartic acid, serine and alanine, while the amounts of threonine, arginine and tyrosine decreased in both species. The polypeptide bands of the HPF in both species were unchanged compared with the raw seed flours, but more intensive coloured bands were observed. Thermal treatments eliminated major and minor bands above 35.0 KDa in both species. Copyright © 2004 Society of Chemical Industry     

萌发苦荞粉的加工和消化特性分析

为探索萌发苦荞粉在食品中的应用,该文研究了苦荞萌发过程中水分含量的变化,并以苦荞原粉为对照,分析了萌发苦荞粉的加工特性（冻融稳定性、凝胶能力、水合特性和透明度）、体外消化模拟过程中还原糖释放率、淀粉的组成以及估计血糖生成指数。结果表明,苦荞含水率在萌发0~3 h时迅速增加,并随时间的延长而缓慢提高;萌发处理显著降低了苦荞粉的冻融稳定性,析水率达18.94%,为苦荞原粉的3.01倍。沉降体积降低了11.30%,表明凝胶能力增强。持水力和膨胀度有一定程度下降,但溶解度显著提升,增加了26.70%。萌发苦荞粉的透光率为4.29%,相对于原粉降低了0.38%;在浸泡15 h、萌发12 h内还原糖释放量持续增大,随后呈下降趋势,最大释放量分别为13.85%和10.67%;20 ℃下浸40 h后,在25 ℃、湿度80%和光照强度7500 Lx的条件下萌发48 h,苦荞淀粉的含量从66.94%下降到59.43%,快消化淀粉的含量提高至85.69%,抗性淀粉含量降低至9.45%;萌发苦荞粉的消化速率显著提高,最终水解率达到92.80%,但水解指数（88.24）和估计血糖生成指数（88.15）上升不显著。因此,萌发苦荞粉相比于苦荞原粉具有更好的凝胶性、溶解性和消化性,适用于制凝胶类和易消化类食品,该研究为萌发苦荞食品的开发提供了一定的理论依据。     

萌发荞麦种子蛋白质组分含量变化的研究

研究了荞麦种子萌发后总蛋白质和各蛋白组分如清蛋白、球蛋白、醇溶蛋白和谷蛋白的含量变化，结果表明：本试验条件下，山西甜荞和四川苦荞萌发后总蛋白质含量呈逐渐下降趋势。山西甜荞经过72h的萌发，其蛋白质总量由最初的11．90％下降到5．44％，下降了6．5个百分点。四川苦荞由萌发初的6．53％下降到0．96％，下降了5．6个百分点。荞麦清蛋白和球蛋白在萌发后均呈现下降趋势，与总蛋白质含量变化相一致。谷蛋白在萌发后至36h内含量下降，之后又快速增加。四川苦荞醇溶蛋白含量在萌发后逐渐增加．而山西甜荞则有逐渐下降趋势。     

不同储藏条件对油葵籽生理品质的影响研究

测定不同储藏条件下油葵籽生理指标的变化情况.结果表明:随着储藏时间的延长,油葵籽色泽、气味逐渐出现异常,生活力、发芽率和过氧化氢酶活度均呈逐渐下降的趋势,且温度和水分越高,下降趋势越明显.因此,低温、低水分是油葵籽安全储藏的主要条件.     

Wheat-bug damage in New Zealand wheats: The feeding mechanism of nysius huttoni and its effect on the morphological and physiological development of wheat

Adult Nysius huttoni White were placed in separate cages containing cultivars Rongotea and Karamu at the late anthesis, watery ripe and milky ripe stages of development. Between 84 and 99 % of the matured kernels were injured with the characteristic visible markings of bug-damaged wheat. All the samples contained strong wheat-bug proteinase activity as shown by the incubated SDS-sedimentation test and the disappearance of HMW glutenin subunits from electrophoretograms. Grain infested at late anthesis was most severely affected with shrivelled kernels, high screenings, protein, free amino acids and α-amylase, and low kernel weight, germination capacity and carbohydrate content. Grain infested at the watery ripe and milky ripe stages had values for the above properties closer to uninfested control wheat values. It was suggested that N huttoni sucked sap from lateral sieve tubes in the wheat ovary at late anthesis causing severe disruption to physiological development of the grain. Two commercial lines of wheat showed some characteristics of this effect.     

大豆种子萌发过程中子叶细胞超微结构和ATP酶活性动态研究

采用磷酸铅沉淀的电镜细胞化学方法，研究大豆种子萌发过程中，子叶细胞超微结构变化与ATP酶活性的消长。子叶细胞的ATP酶活性主要定位在质膜。在种子萌发的0-3天，子叶细胞贮存蛋白质和油脂大量急剧降解，并快速转运到胚，质膜ATP酶活性较高。萌发的6-9天，子叶细胞内含物大部分消解，蛋白体膜相互融合形成大液泡，原质体开始有稀疏的片层结构，ATP酶活性渐弱至无。萌发第12天，原质体的片层堆叠成基粒，子叶细胞转为同化器官，制造养分，质膜再度呈现较强的ATP酶活性。子叶细胞质膜ATP酶活性反应子叶细胞生理代谢状态。