碱性蛋白酶对麦胚蛋白水解作用的研究

试验研究了碱性蛋白酶对麦胚蛋白的水解效果。结果表明：碱性蛋白酶水解麦胚蛋白的最佳水解条件是pH值8.5、温度50℃、加酶量0.4 AU/g、底物浓度1%水解150 min,该条件下水解度可达35.62%。试验对水解物的氨基酸组成进行了测定与分析。     

生物酶法制取黑豆速食粉的研究

通过设计单因素试验和响应面分析试验，根据酶添加量、酶解时间、水解温度3个因素对黑豆粉糊液黏度的影响，优化了黑豆速食粉的制备工艺。通过响应面设计优化最佳工艺条件：酶添加量为4．85U／g，酶解时间为21．32min，水解温度为69．77℃，黑豆粉糊液黏度为48．92mPa·s，比未处理的黑豆粉糊液下降了43．05mPa·s，影响黑豆粉糊液黏度主要因素依次是温度、添加量、时间。     

大米淀粉酶法制糖工艺研究

以大米淀粉为原料，研究大米淀粉酶法水解制糖工艺，以加酶量、温度、时间、料水比作为考察因素，采用正交试验优选大米酶解制糖的较佳工艺条件是α－淀粉酶添加量15U／g、温度55℃，时间30min、料水比1：9.     

酶解芝麻粕制备芝麻多肽工艺研究

以芝麻粕为原料,利用多种蛋白酶对芝麻蛋白进行水解,最后选择碱性蛋白酶、中性蛋白酶以及木瓜蛋白酶3种进行复合酶解。在固定料液比为1：5和加酶顺序为碱性-中性-木瓜的条件下,得出酶解的最佳工艺参数为：碱性蛋白酶的加酶量为0．5％,pH为9．5,温度50℃,酶解时间为2h;中性蛋白酶的加酶量为0．6％,pH为7．5,温度35℃,酶解时间为3h;木瓜蛋白酶的加酶量为1．5％,pH为6．5,温度50℃,酶解时间为3h。酶解后,总氮回收率达到63．14％,三氯乙酸可溶性氮指数可达55．11％,多肽转换率可达48．99％。     

乳清蛋白ACE抑制肽酶解工艺纯化研究

为充分利用奶酪制作的副产物——乳清蛋白增加乳制品附加值,本研究以浓缩乳清蛋白为试验原料,采用酶解技术制备乳清蛋白ACE(Angiotensin Converting Enzyme)抑制肽。在酶的筛选试验中,以酶解产物ACE抑制率和肽得率为指标选出最佳水解用酶为Alcalase 2.4L碱性蛋白酶,然后采用单因素试验得到了此酶的最佳水解条件并对水解物的稳定性进行了试验。研究结果表明,最适酶解条件为底物浓度7.5%、加酶量6 000U/g、pH值8.5、温度55℃,得到酶解产物ACE抑制率为69.38%、IC_(50)为0.80mg/mL,经模拟肠胃消化处理后,肽的活性并无显著变化,稳定性较好。经葡聚糖凝胶纯化后,抑制率提升至75.33%,其IC_(50)为0.74mg/mL。     

双酶切制备富含谷氨酰胺的小麦水解蛋白及相关研究

以小麦面筋蛋白为原料,用Alcalase2.4L碱性蛋白酶和Protamex复合蛋白酶为酶解剂对其进行双步水解制备富含谷氨酰胺的小麦水解蛋白,通过响应面法对双步水解工艺进行了优化.通过优化后的制备工艺为：在底物浓度4％、温度60℃、pH8.5、Alcalase2.4L碱性蛋白酶加酶量2％,酶解2h,再调节温度50℃、pH7.0条件下加Protamex复合蛋白酶1％酶解1h;此时小麦水解蛋白的谷氨酰胺肽含量达到31.2％,小于1 000 kDa分子质量的肽段占40.34％,水解前后电镜扫描图也有了明显差异。     

超声波辅助酶法优化茶陵白芷多糖提取工艺的研究

本文以茶陵白芷为原料,采用超声波辅助纤维素酶法提取茶陵白芷多糖,通过单因素试验,研究纤维素酶添加量、酶解pH值、酶解温度和酶解时间4个因素对茶陵白芷多糖提取率的影响,并对其最佳工艺进行正交试验优化.结果表明,超声波辅助纤维素酶法提取茶陵白芷多糖提取率的影响因素主次排列顺序为酶解pH值>酶解温度>酶添加量>酶解时间,超声...     

响应面优化纤维素酶对沙棘低聚糖提取率影响的研究

本试验以沙棘粕为原料,加入适量纤维素酶经酶解反应后得沙棘低聚糖,以低聚糖提取率为测定指标,同时采用单因素及响应面对酶解pH、酶解温度、酶解时间、酶添加量进行优化。结果表明:酶解pH为6,酶解温度为50℃,酶解时间为4.5h,纤维素酶添加量条件为0.4%,在此条件下测得沙棘低聚糖的提取率为42.81%,沙棘低聚糖的含量为84%。通过试验,对沙棘提取低聚糖工艺进行深入研究,利用响应面优化得出确定最佳条件,为进一步开放沙棘低聚糖的提取提供理论依据。     

大米蛋白的双酶法制备工艺研究

利用双酶法制备大米蛋白，通过不同蛋白酶的酶解实验，得出胰蛋白酶的产品质量和收率的综合指标最优，并比较得出最优的米渣水解用酶为胰蛋白酶，通过单因素和正交实验得出胰蛋白酶酶解的最佳工艺条件：加酶量为0.2％，酶解pH为7.4，酶解温度为40-45℃，酶解时间为14h。为进一步改善大米蛋白的质量，通过分析和实验验证，提出了在胰蛋白酶酶解过程中添加高效蛋白酶制备优质大米蛋白的工艺方法。     

柑橘蒲公英保健饮料加工工艺的研究

以柑橘和蒲公英为主要原料,研制柑橘蒲公英保健饮料,并探讨各因素对柑橘汁酶解、蒲公英浸提及饮料调配效果的影响。结果表明,柑橘汁的最佳酶解工艺为果胶酶和纤维素酶按1∶3的比例添加,添加量为0.6%,pH值3.0,时间3h、温度50℃;蒲公英的最佳超声浸提条件为超声频率40 kHz,料水比1∶30,温度80℃,提取2次,每次1.0h;饮料最佳调配工艺为冰糖10%、蒲公英浸提液20%、柑橘汁8%、CMC 0.3%、柠檬酸0.2%,在此条件下制得的产品风味独特,营养丰富,质量最佳。     

Income Growth and International Meat Consumption

With technological adoption and trade liberalization, per capita incomes have grown rapidly in industrialized countries. Income growth has resulted in increased per capita meat consumption. Projecting future meat consumption requires quantifying the relationship between per capita income and meat consumption. This study estimates the relationship between income growth and meat consumption using data from 32 countries. Beef, pork, poultry, and lamb income elasticities declined at different rates as income levels increased. High income countries have experienced relatively constant per capita meat consumption. Low income counmes with low income growth have had stagnant meat consumption. Low income countries with growing incomes have experienced increasing meat consumption. Countries such as China characterized by relatively large income growth and moderate population growth have experienced large increases in total meat consumption.     

Meat Demand under Rational Habit Persistence

The objective of this paper is to explore the theoretical implications of a meat demand model with rational habit formation. The impact of food safety information on meat consumption is systematically analyzed. Important differences between myopic habits and rational habits are underscored. Both the adjustment path to the new equilibrium and new level of consumption are affected by consumers' perceptions of changes in meat quality. The analysis has implications for empirical demand estimation by incorporating consumers' expectations and use of event dummy variables rather than index measures of food safety.
Le présent article vise à explorer les implications théoriques d'un modèle de demande de viande avec formation d'habitudes rationnelles. Les répercussions de l'information concernant la sécurité alimentaire sur la consommation de viande ont été systématiquement analysées. Les différences importantes entre les habitudes rationnelles et les habitudes myopes ont été soulignées. Le chemin de rajustement du nouvel équilibre et du nouveau degré de consommation est affecté par la façon dont les consommateurs perçoivent les changements dans la qualité de la viande. L'analyse a des implications pour l'estimation empirique de la demande en raison de l'intégration des attentes des consommateurs et de l'utilisation de variables fictives plutôt que de mesures indicielles de la sécurité alimentaire.     

Structural Change in Canadian Meat Demand

Results derived from a time-varying parameterization of the AIDS model provide evidence of a structural change in Canadian meat demand (beef, pork, chicken). The structural change was accompanied with significant changes in some of the parameters of the model, and was biased in favor of chicken at the expense of beef.
Les résultats d'une paramétrisation du modèle AIDS variant dans le temps indiquent une modification structurelle de la demande de viande (boeuf, pore, poulet) au Canada. Cette modification structurelle a été accompagnée par des changements importants à certains paramètres du modèle et semble favoriser le poulet aux dépens du boeuf.     

Consumer Valuation of Alternative Meat Origin Labels

Results from a split‐sample survey of the US population reveal consumers prefer meat products carrying origin information to unlabelled alternatives. Consumers are largely unaware of origin labelling laws and are indifferent to an important aspect of the implementation of current mandatory country of origin information rules in the US. In particular, consumers value meat products labelled ‘Product of North America’ approximately the same as ‘Product of United States’. Despite the similarity of these two labels, they have vastly different implications in terms of trade and segregation costs. Our results suggest that a transition from one label to the other is equally satisfying for the consumer while being less costly for processors and more acceptable to trade partners.     

Gradual Structural Changes of Meat Consumption in Taiwan

Abstract

This paper utilized a linear approximate version of the Almost Ideal Demand System to evaluate structural changes of meat consumption in Taiwan. Time transition paths for each product were identified, and the first-order autocorrelation was taken into consideration. Structural changes of beef consumption were completed before structural changes of other products had started. Shifts in consumption patterns of pork and poultry took about the same length of time. Structural changes of fishery products occurred toward the end of the time period. With the gradual switching time paths, estimated elasticities revealed that own-price elasticities for pork, beef, and fishery products became more responsive to their own-price changes.     

Economic Development,Income Distribution and Meat Demand

Meta-Engel curves for meats are estimated from international cross-section data. Income explains a large proportion of meat consumption variance and tastes are relativefy unimportant. Growth in meat consumption accelerates as countries pass through the middle income stage. Greater equality in income distribution reduces average meat consumption, Therefore, part of the reason why growth In meat consumption accelerates as countries pass through the middle income stage is because income distribution is more skewed at that stage of development.     

花生风味兔肉脯配方的研究

花生粉富含蛋白质且在烘烤后具有浓郁的香气,将其作为主要配料添加到兔肉糜中,制备花生风味兔肉脯.通过单因素试验和正交试验,以感官评分?质构特性及色差为考察指标,研究糖盐比?花生粉和大豆分离蛋白添加量对兔肉脯品质的影响,优化兔肉脯配方.结果表明,最佳配方为糖盐比8.5:1.5?花生粉添加量15％?大豆分离蛋白添加量4％.此...     

加快形成优势产区 积极应对入世挑战

优化农业区域布局是农业结构战略性调整的一个重要内容，因地制宜地确定区域主导产业，加快形成集中优势产区，促进优势农产品生产区域化，规模化，对于提高我国农业的整体素质和效益，增强农产品的国际竞争力有重大意义，应当作为调整农业结构，应对入世挑战的一项重要而紧迫的工作来抓，本文对推进优势农产品区域化布局进行了论述。     

蒸肉蒸菜粉的营养及开发进展研究

目前国内对传统特色食品的现代化、方便化生产技术的研究非常重视。主要介绍我国传统蒸菜所用的蒸肉蒸菜粉,综述了蒸肉蒸菜粉的营养特性及目前的相关研究和开发进展,并对其前景进行了展望。