NFC苹果浊汁褐变与品质相关性研究

褐变是果汁品质劣变的重要因素之一.通过模拟NFC苹果浊汁开封后在未完全密闭状态下,于4℃和20℃短期贮藏期间的自然褐变过程,探讨苹果浊汁褐变过程与营养及风味变化的关系.结果表明,NFC苹果浊汁贮藏过程中褐变程度受贮藏温度和时间的直接影响.在两种贮藏温度下,果汁颜色均随贮藏时间延长不断加深,总酚和维生素C含量逐渐下降;可溶性固形物含量降低和可滴定酸含量增高导致糖酸比下降.20℃贮藏期间,果汁品质劣变迅速;4℃贮藏初期,果汁品质变化不明显,但在后期劣变速度明显加快.NFC苹果浊汁在贮藏前期芳香族化合物、氮氧化合物等挥发性风味物质有所减少,而在贮藏后期碳氢化合物、无机硫化物、烷烃类和脂肪族类物质逐渐增加.褐变与NFC苹果浊汁品质指标的相关性分析表明:冷藏条件下褐变程度与浊汁口味和挥发性风味的相关性更强,而常温贮藏下与浊汁营养物质含量的相关性更强.研究结果可丰富果汁贮藏机理,以期为苹果浊汁加工及开封后短期贮藏过程中品质变化研究及调控提供理论借鉴.     

金枪鱼头的营养成分及其蛋白酶解物的应用

对黄鳍金枪鱼鱼头的营养成分进行了分析，并对其蛋白质营养价值进行了评价。结果显示，金枪鱼头粗蛋白含量干基计为68．0％，脂肪27．2％，含有丰富的钠和钙；根据1973年FAO／WHO推荐的必需氨基酸需要量模式对金枪鱼头蛋白进行评价，氨基酸评分为60，第一限制性氨基酸为色氨酸。用木瓜蛋白酶和风味酶双酶同时酶解金枪鱼头蛋白，酶解液经调配制得营养液，其总氮为1．02g／100mL，氨基酸总量为986．81mg／100mL。     

挂面包装机包卷装置的设计与研究

通过包卷装置实现挂面的卷纸和包装,采用拨轮机构和不完全齿轮机构实现个动作的时间协调,包卷过程则采用循环牵引机构带动包装带,并带动包装纸和散装挂面在包卷装置中做纯滚动,从而实现卷纸动作;同时使用凸轮振动装置将挂面振实;包装带牵引装置由不完全齿轮机构和具有急回特性的曲柄摇杆机构相配合组成。     

不同烹调方法对野生蔬菜营养成分的影响

研究了油炒、漂烫和微波三种烹调方法对野生蔬菜蒲公英、荠菜一些营养成分的影响。结果表明,与对照相比,油炒使蒲公英、荠菜的总酸性物质含量增加,氨基态氮、维生素C、可溶性糖含量降低;漂烫均导致蒲公英、荠菜的氨基态氮、总酸性物质、雏生素C、可溶性糖含量降低;微波使蒲公英、荠菜的总酸性物质、可溶性糖含量增加,维生素C、氨基态氮含量降低。综合这些分析结果,从保存营养成分的角度考虑,野生蔬菜在食用方法上还是以微波方法最好。     

预包装肉制品营养标签的制作

对预包装肉制品营养标签的制作提出建议,帮助生产者正确进行营养信息的标注。严格按照标准规定,讨论预包装肉制品营养标签的制作要点。生产者应当全面把握、正确理解营养标签的有关标准和知识,为消费者提供准确的营养信息。     

螠蛏的营养及活性成分研究进展

螠蛏作为一种海洋双贝壳类软体动物具有较高的营养价值和许多功能性成分.这些活性物质成为了功能性食品、保健品等的开发热点.对蜢蛏的营养和功能性成分的研究现状及其前景进行概述.     

Metabolic effects in mice of cream formulation: Addition of both thickener and emulsifier does not alter lipid metabolism but modulates mucus cells and intestinal endoplasmic reticulum stress

Additives stabilize or improve the organoleptic or functional properties (or both) of many dairy products including whipping cream. Their influence on the metabolic effect of dairy cream is scarcely known. We tested the hypothesis that added emulsifier (lactic acid esters of mono- and diglycerides; MAG/DAG), thickener (carrageenan, CGN), or both, could modify the metabolic effect, notably in the intestine and liver. Nine-week-old male C57Bl/6J mice were fed UHT cream (indirect treatment) mixed with nonlipidic powder (final: 13% milkfat) for 1 or 4 wk. We compared creams (1) without additive (Ctl), (2) with thickener (Th), 0.02% of κ-CGN, and (3) with both thickener and emulsifier, 0.1% of MAG/DAG esters (Th/Em). We analyzed plasma parameters, intestine, and liver. Fasting glycemia, insulinemia, triglyceridemia, nonesterified fatty acids, body weight gain, and liver weight did not differ among groups. After 1 wk, Th/Em had higher expression in the duodenum of some of the genes involved in (1) intestinal lipid absorption and (2) tight junction proteins versus Ctl and Th. After 4 wk, mucus cell number in the small intestine was higher in Th/Em versus Ctl and Th. Genes involved in endoplasmic reticulum (ER) stress in the duodenum were more expressed in Th/Em after 1 wk. After 4 wk, in the colon, a higher expression of ER stress genes was observed for Th versus Th/Em and Ctl. Liver damage score was not altered by additives. Adding both CGN (0.02%) and MAG/DAG esters (0.1%) in dairy cream did not result in deleterious outcomes in mice after 4 wk regarding lipid metabolism, intestinal permeability, and liver disorders. The longer term effect of intestinal ER stress modulation deserves further investigation.     

Dephytinisation of rice bran and manufacturing a new food ingredient

Rice bran was extruded at 130 °C and a screw speed of 140 rpm for 20 s to inactivate lipase and prevent lipid oxidation. Although the extrusion process induced further complex formation between phytic acid and protein as well as between phytic acid and starch, nearly 94% of phytic acid in the extruded rice bran could still be removed by solid/liquid extraction conducted at 25 °C for 30 min using hydrochloric acid at pH 2 as solvent and a solvent/rice bran ratio of 15. After the extract had been neutralised and phytic acid removed, it was added back to the rice bran solid to replenish the nutritional and functional components of the solid. The mixture was then dried in a drum dryer to yield a powdered product. The dephytinised rice bran product contained most of the protein, fat, dietary fibre and B vitamins and more than 50% of the oryzanol originally present in the raw rice bran. © 2001 Society of Chemical Industry     

基因食品的营养与安全分析

转基因食品是人类科技发展史上的新生事物。本文就基因食品的营养成分、加工过程营养稳定性、营养素的生物利用及功效等进行了详细分析,对基因食品的安全隐患及其合理评价原则进行了理性的分析,提出了基因食品未来的发展方向,只要人们以科学、理智的态度来培养它,转基因食品就会沿着科学的轨道健康发展。     

预包装快餐食品营养标签的制作

按照《食品安全国家标准预包装食品标签通则》及《食品营养标签管理规范》的要求测定了19种预包装快餐食品的4种核心营养成分(蛋白质、脂肪、碳水化合物、钠)及能量,并设计营养标签。快餐食品标示营养标签势在必行,可使消费者根据自身营养需求选择合适的食物,也可规范餐饮业生产行为,生产出健康、营养的美食。