Firmness of Canned Grapefruit Sections Improved with Calcium Lactate

Hand cut commercially produced grapefruit sections, packed in either juice or syrup, were treated with 0._-l-0.5% calcium lactate throughout the 1988–1989 season and monitored for changes in shear force resistance. Firmness of both juice and syrup control packs declined about 40% during the processing season. Calcium addition did not reverse seasonal softening but incrementally decreased loss of firmness during processing. Improvements in texture were independent of seasonal changes, and remained relatively constant throughout the season. Optimal levels of calcium lactate were 0.3–0.4% for juice packed sections and the highest level used (0.5%) for syrup packed sections. Maximum increases in firming due to calcium in juice and syrup packed sections were 38 and 50%, respectively.     

典型农林废弃物处理含铬废水的研究进展

介绍了花生壳、木屑、柚子皮、玉米秸秆及玉米芯等5种典型农林废弃物在处理含铬废水中的应用和处理效果,并展望了其应用前景。     

柚子活性成分的提取及其功能研究进展

柚子不仅具有丰富的营养价值,而且具有重要的生物学功能。对柚子的有效部位进行简要说明,着重对柚子的活性成分及其生理功能进行详细阐述,并对其发展前景进行展望,以期为我国柚子资源的开发利用提供参考。     

Albedo hydrolysis modelling and digestion with reused effluents in the enzymatic peeling process of grapefruits

BACKGROUND: Until now, the optimisation of enzymatic peeling of grapefruit in the reactor has been obtained as the result of the semi‐qualitative effects of enzyme activity. This work is an attempt to obtain quantified data. The reuse of enzymes to reduce costs in this process is unprecedented in the literature and is the aim of the present work. RESULTS: The optimal conditions determined for the maximum albedo degradation were a temperature of 40.6 °C and a time of 13.1 min in an enzymatic concentration of 0.067 mL enzymatic preparation per gram of peel in each litre of citrate buffer solution. The decrease in relative enzymatic activities in reused effluents was determined, as was the increase in activity when the enzymes were purified. These increases were 15.5% for polygalacturonase and 15.4% for cellulase activity. CONCLUSION: Optimal temperature, time and the ratio between peel mass and the enzymatic preparation volume were the best conditions for obtaining good peeling efficiency. The effluents from the enzymatic peeling process of the grapefruit still contain appreciable enzymatic activity after the digestion process. Thus, reusing these effluents while maintaining peeling efficacy and a subsequent recovery of the active enzymes by ultra‐filtration of the effluents is the way to improve the efficiency of the process. Copyright © 2010 Society of Chemical Industry     

Effects of distillation cut on the distribution of higher alcohols and esters in brandy produced from three plum varieties

The purpose of this investigation was to determinate effects of distillation cuts on the distributions of higher alcohols (1‐propanol, 2‐methyl‐1‐propanol, 3‐methyl‐1‐butanol, 2‐methyl‐1‐butanol, 1‐butanol, 2‐butanol, 1‐hexanol and 1‐pentanol) and esters (ethyl acetate, isopentyl acetate + ethyl lactate, isobutyl acetate, ethyl propionate and ethyl butyrate) in plum brandy. The volatiles were determined by gas chromatography–flame ionization detection. The three most popular plum varieties used in plum brandy (Sljivovica) production, Stanley, Pozegaca and Bilska rana (Buhler), were distilled using a traditional distilling pot and fraction distillation. Three distillation cuts were considered. After separating the head fraction, in the amount of 1.7% of the distilling pot volume, heart fractions were cut at 40, 45 and 50% (v/v) ethanol and tail fractions, analogous to the heart fraction, were collected up to 10% (v/v) ethanol. The ratio of the content of 2‐methyl‐1‐propanol and 3‐methyl‐1‐butanol was 1:1 in the plum brandy produced from Stanley and Pozegaca and the ratio was 2:1 in the plum brandy produced from Bilska rana. This ratio can be used as a ‘mark’ of variety recognition in plum brandy production. The main differences in the heart fraction were accounted for by the content of the higher alcohols and esters for the distilling cut at 40 and 50% (v/v) ethanol. Copyright © 2013 The Institute of Brewing & Distilling.     

霜后采收对北国蓝葡萄酒及蒸馏酒香气成分的影响

以山葡萄北国蓝为实验材料,研究霜后采收对葡萄果实、葡萄酒及葡萄蒸馏酒挥发性香气成分的影响。实验内容:分别对9月14日、10月15日采收的北国蓝葡萄进行酿酒及蒸馏试验,并测定各理化指标及香气成分。结果表明,10月15日采收的果实总糖含量(266.17 g/L±0.08 g/L)显著高于9月14日采收的(167.32 g/L±2.44 g/L),且总酚含量也高于9月14日采收的;10月15日采收的葡萄酒的香气成分的含量(182925.0254μg/L)明显高于9月14日采收的(14523.386μg/L);但9月14日采收的烈酒的香气成分的含量(15915.21μg/L)略高于10月15日采收的(14030.459μg/L)。     

加速白兰地陈化的研究

研究了在白兰地中加入天然陈化剂的陈化效果。在白兰地中加入经过不同处理、不同品种、不同量的天然陈化剂,在变温条件下进行陈化实验,并利用分光光度计测其吸光度、气相色谱测定乙酸乙酯等色谱骨架成分。结果表明:在变温储藏条件下,经过2%NaHCO3处理的中国橡木CH,添加量为2%时,陈化白兰地的效果较好。     

猕猴桃白兰地专用酵母菌的选育及鉴定

通过2,3,5-三苯基氯化四氮唑(TTC)显色、产气初筛及发酵复筛方法在猕猴桃自然发酵液中筛选出了2株酿造性能良好,产酯能力较强的酵母N5和N13,其酿造出的猕猴桃白兰地一次蒸馏产物香气纯正,浓郁,无异味,一次蒸馏液乙醇体积分数分别为8.6%和9.1%,其中N5酵母酿造产物中丁酸乙酯的含量为0.122 g/L,N13酵母酿造产物中乙酸乙酯的含量为0.150 g/L,其产酯能力均明显提高。经过形态学及分子生物学鉴定,N5和N13菌株均属于汉逊酵母属。