果汁型橙汁囊胞饮料的悬浮稳定性研究

本文通过提高果汁含量和选用效果良好的复配增稠剂对柑橘为原料制成的果汁型橙汁囊胞饮料的悬浮稳定性进行了研究,同时采用SPME-GC-MS技术对其几种主要香气物质进行了鉴定分析,并研究了其流变特性。实验结果表明,0.2%黄原胶+0.25%果胶,0.15%CMC+0.2%黄原胶+0.1%果胶,0.1%CMC+0.05%黄原胶+0.1%琼脂和0.1%黄原胶+0.1%果胶+0.1%琼脂等4种不同组成的复合稳定剂对果汁型橙汁囊胞饮料的悬浮效果良好;添加了增稠剂的果汁更加稳定,且为非牛顿流体,呈典型的假塑性流体特征,且添加增稠剂对橙汁囊胞饮料中的几种主要香气物质的释放造成了一定影响,不同组成的增稠剂对其影响也不太相同,其中3-蒈烯、d-柠檬烯、β-香叶烯、γ-萜品烯和紫苏醛被检出的含量均出现明显降低,但饮料的表观粘度与香气释放没有直接的关系。     

Free and Bound Volatile Secondary Metabolites of Vitis Vhifera Grape cv. Sauvignon Blanc

Free volatiles, and those hydrolytically released from glycosidic forms, were analyzed for Sauvignon Blanc juices from three successive vintages. Most of the 213 compounds identified were in one of the bio-genetic categories: norisoprenoids, benzene derivatives, monoterpenes or aliphatics. Several have not been previously reported as grape components. Monoterpenes were in lower concentration than normally found in floral grape varieties, but at higher levels than reported in Chardonnay juices. A notable proportion (40–50%) of the bound monoterpenes were monocyclic. Hydration of α-terpineol at pH 3 gave c-4-(1-hydroxy-1-methyIethyl)-1-methyl-r-1-cyclohexanol (cis-p-men-thane-1,8-diol) and t-4-(1-hydroxy-1-methylethyl)-1-methyl-r-1-cy-clohexanol (trans-p-menthane-1,8-diol) as the main products and a low yield of t-4-(1-methylethyl)-r-1-methylcyclohexane-1,4-diol (trans-p-menthane-1,4-diol). These were confirmed as major components of the acid hydrolysates of the bound fraction.     

Effects of rind removal on physicochemical quality characteristics of fresh‐cut watermelon [Citrullus lanatus (Thunb) Matsum & Nakai] during cold storage

The impact of removing the rind from fresh‐cut watermelon slices was assessed on the quality of the product during storage at 4 °C for 9 days. Flesh lycopene declined from 55.4 to 47.9 mg kg^?1 f.w. and colour lightness (L*) increased from 43.2 to 45.8 after 2 days of storage. Initial heart and placental flesh firmness increased from 7.3 and 9.8 N, respectively, to 9.5 and 12.8 N after 9 days, but were unaffected by rind processing. Electrolyte leakage from placental tissue was unaffected by storage and rind. Rind presence limited juice run‐off by 47.2% and maintained mean total soluble sugar concentration in the slices at 86.0 mg mL^?1 as opposed to 76.8 mg mL^?1 in rind‐less slices. Change in the quality was most pronounced between 0 and 2 day of storage. Removing the rind accelerated senescence and off‐flavour production, while the presence of rind improved the overall storage stability of fresh‐cut watermelon slices.     

臭氧对苹果汁中棒曲霉素的降解效果研究

主要研究臭氧对苹果汁中棒曲霉素(Pat)的降解效果及对果汁品质的影响。研究采用臭氧对水和苹果汁中500、250、200、100、50μg/LPat浓度进行5、10、15、20、30min的降解处理。结果表明,臭氧处理对各浓度的Pat都有降解作用,浓度越低,降解效果越好。随着处理时间延长降解效果越好,15min以后降解率不再增加。臭氧处理15min,50μg/L的Pat降解效率最佳,在该条件下,臭氧对苹果汁的pH、VC含量、可溶性固形物和色值均没有明显的影响,因此,臭氧处理是高效、安全、低廉的Pat降解方法。      

功能性番茄饮料工艺研究

以番茄为原料进行饮料的加工,针对提高番茄出汁率、饮料稳定性、饮料色泽的保持工艺研究实验,结果发现,对番茄预热后,再加果胶酶处理、加压过滤工艺可使番茄的出汁率达到81.5%,提高了番茄的利用率;番茄饮料中添加2‰,质量比5:2:3的羧甲基纤维素钠、黄原胶、琼脂复配增稠剂可使饮料在常温保存三个月仍具有良好的稳定性。通过实验研制出营养丰富、色泽鲜艳、风味自然、功能性强的番茄饮料。     

果汁非酶褐变的机制及控制措施

本文阐述了果汁非酶褐变的机制：焦糖化反应、美拉德反应、抗坏血酸氧化分解和多元酚氧化缩合,并对目前常用的抑制果汁非酶褐变的方法进行了综述.     

HACCP管理系统在浓缩梨汁生产中的应用

在浓缩梨汁生产管理中,通过推行HACCP管理系统,对其生产进行规范.要求对整个生产工艺过程中的关键点进行严格的质量控制,以确保产品的质量,同时为其它果蔬浓缩汁提供了有益的借鉴.     

芦荟、梨、黄瓜复合果蔬汁的加工工艺

以芦荟、梨和黄瓜为主要原料，研究了营养保健型复合果蔬汁的制作工艺。采用对比、正交实验设计，确定了最佳工艺参数，该产品具有较高的营养价值。     

苦荞麦保健醋酿造工艺研究

以苦荞为原料，辅加10％的复合果汁，采用液体深层发酵生产工艺，研究了发酵过程中各主要成分的变化，并确定了加工工艺参数。酒精发酵采用耐高温活性酒精干酵母(TH-AADY)，添加量为0．2g／L，发酵温度30℃，发酵时间3～4d；醋酸发酵采用AS1.41，发酵温度35℃，发酵时间3～4d．醋酸可达4．9g／100mL以上。     

基于尿苷二磷酸葡萄糖醛酸转移酶1解毒通路探讨枸杞汁对邻苯二甲酸二(2-乙基己基)酯代谢的干预作用

目的:通过大鼠毒性干预实验观察枸杞汁对邻苯二甲酸二(2-乙基己基)酯(di-(2-ethylhexyl)phthalate,DEHP)染毒大鼠肝脏中尿苷二磷酸葡萄糖醛酸转移酶1(uridine diphosphate glucuronosyltransferase 1,UGT1)活性及代谢解毒的影响,探讨枸杞汁对DEHP代谢的干预效果。方法:60只雄性大鼠随机分为对照组、DEHP组和枸杞汁干预组,每组20只,DEHP组和干预组在DEHP一次染毒(3 000 mg/kg mb)后连续7 d分别灌胃生理盐水和枸杞汁,对照组则给予同等体积的芝麻油或生理盐水,期间每天收集大鼠24 h尿液。在染毒1、3、5、7 d后各组分别随机处死5只。采用试剂盒检测肝脏UGT1的活力,高效液相色谱法检测血清中的邻苯二甲酸单(2-乙基己基)酯(mono-(2-ethylhexyl)phthalate,MEHP)以及尿液MEHP和邻苯二甲酸(phthalic acid,PA)含量。结果:枸杞汁干预组大鼠第5天UGT1活性显著高于DEHP组和对照组(P0.05),且相对于DEHP组血清中MEHP含量减少而尿液中MEHP和PA含量增加。结论:枸杞汁可能通过提高UGT1活力促进了DEHP的代谢与排泄,发挥了解毒效应,将来可能作为一种预防或对抗邻苯二甲酸酯类物质或其他有毒化学物潜在危害的保健药材或功能食品用于人群的健康防护。