Effect of synthetic microbial community on nutraceutical and sensory qualities of kombucha

To mass-produce nutritional kombucha with quality consistency, it is necessary to design synthetic microbial community (SMC) starters with clear bacterial compositions. In this study, a three-species SMC, including Acetobacter pasteurianus, Gluconacetobacter xylinus and Zygosaccharomyces bailii, was designed. Acetic acid bacteria (AAB) in SMC produced a higher concentration of organic acids synergistically compared to each strain inoculated alone. Gluconic acid was the most abundant organic acid in kombucha fermented by SMC, which contributed to the pleasant sour taste of the beverage. AAB could also oxidise the alcohol produced by Z. bailii, making kombucha a soft beverage. Total phenol and flavonoid concentrations increased during fermentation, which enhanced the health benefits of kombucha. The sensory evaluation demonstrated tsshat sensory attributes of SMC fermented kombucha were quite similar to those fermented by the symbiotic culture of bacteria and yeast (SCOBY). Therefore, SMC could be utilised in the industrial mass production of kombucha for better quality control and product consistency.     

肉丸的食用品质特性研究

用猪、牛肉（各５０％）为原料,通过添加不同的配料生产肉丸子,并用仪器对各组肉丸的品质特性进行客观评价。结果表明：１滋嫩度：Ｂ组、Ｃ组优于对照组和Ａ组（Ｐ＜０．０１）,Ａ组优于对照组（Ｐ＜０．０５）;２色泽：对照组、Ａ组的色泽略深于Ｂ组、Ｃ组（Ｐ＞０．０５）;３感官评定：各组综合评分结果为良好,其中Ｂ组的香味、口感等食用性能最佳。说明适量添加淀粉、肥膘等于肉丸中,能改善其食用性能;猪、牛肉混合生产的肉丸子,其食用特性优于牛肉丸子。     

Influence of malaxation conditions on characteristic qualities of olive oil

While there has been considerable work examining the effect of extraction methods and malaxation conditions on different characteristics of olive oils, there have been few that deal with all the major aspects. Here we have evaluated three different extraction techniques and the influence of time and temperature during malaxation using a major Italian (cv. Coratina) and the main Cretan (cv. Koroneiki) cultivars. Standard characteristics were measured as well as detailed analyses of alcohols, steroids and phenolics were conducted. Quality was also assessed by Panel tests. The main variables were the total amount and composition of the phenolics. In turn, this influenced the oxidative stability and sensory quality. It was also clear that the cultivars behaved differently and this prevented general conclusions being made for all of the quality characteristics.     

间歇真空发酵对辣木茶感官品质的影响

采用3因子2水平的正交试验设计,研究了发酵温度、发酵时间、间歇真空处理对辣木茶感官品质的影响。试验结果表明：影响辣木茶感官评分的因子重要性为发酵时间＞间歇真空条件＞发酵温度。发酵时间和间歇真空处理对辣木茶的感官评分分别有极显著（P＜0.01）和显著（P＜0.05）的影响。最佳的工艺组合为发酵温度35℃、发酵时间6 h、(-0.10 Mpa + 2 min)/2 h间歇真空处理,制得的辣木发酵茶感官评分达8.1分。     

运用逐步回归方法建立牛肉感官品质预测模型

为分析牛肉感官品质与理化指标之间的相关性,并利用测定的理化指标建立感官品质的预测模型,该文采集9头牛的背最长肌、臀股二头肌、股直肌、股外侧肌、股中间肌和三角牛霖得到54份样品。通过消费者感官评定和测定样品理化指标,分析了牛肉理化指标与感官评定值的线性关系,大部分理化指标均与感官评定值呈显著或极显著(p<0.05或p<0.01)的相关关系。最后以牛肉理化指标为自变量,感官指标为因变量进行逐步回归分析,分别得到了具有统计意义的牛肉感官嫩度、多汁性、风味和总体评价的预测方程,方程决定系数(R2)分别为0.55、0.37、0.68和0.36。通过预测模型,理化指标可以较好的描述牛肉感官特性。      

Effect of some technological parameters on microbiological, chemical and sensory qualities of Civil cheese during ripening

The objective of this research was to determine the effects of different ripening methods [brine salting, dry salting, incorporating with Lor cheese (LR) and vacuum packaging] of Civil cheeses on its microbiological, chemical and sensory properties. Civil cheeses were analysed on the 2nd, 30th, 60th and 90th day of ripening. Chemical compositions of the cheeses were significantly different. While the highest dry matter and titratable acidity values were determined on dry salted cheeses, the highest fat and fat in dry matter contents were found in Civil cheese ripened together with LR. The water-soluble nitrogen and ripening index values were lower in cheese ripened incorporating with LR. Excessive proteolysis was not seen in any of cheese samples. The ripening in different methods affected microbiological and sensory properties of Civil cheese. Panellists preferred vacuum packaging and dry-salting cheeses compared to the other samples on the 90th day of ripening.     

发酵香肠理化特性和感官质量相关性研究

对市售26种发酵香肠的理化特性和感官指标及相互间相关关系进行了研究。通过酸价、酸度、过氧化值、游离脂肪酸、pH值、挥发性盐基氮、水分含量、脂肪含量、直径与感官质量评测发现，市售各品种发酵香肠理化特性与感官质量指标存在较大差异，理化特性和感官质量的相关性研究表明，水分含量，酸价，游离脂肪酸，pH值等应作为发酵香肠品质设计、管理的必要理化指标。     

Cocoa substitute: Evaluation of sensory qualities and flavour stability

In the past few years, the price of cocoa has climbed very rapidly, so there is increasing incentive in food industry to find a real cocoa substitute. A mixture of milled chicory roots and carob pods (1:2, w/w) was used for preparation of real cocoa substitute via Maillard technology. Comparative studies concerning sensory characteristics and headspace volatiles were carried out between the real cocoa and prepared cocoa substitute. The sensory evaluation revealed high quality of the cocoa substitute sample in comparison with the real cocoa sample. The comparative odour profile analysis showed that the cocoa-like and sweetish/caramel attributes scored higher in cocoa sample than in cocoa substitute sample, whereas the roasty/earthy attributes showed an opposite trend. The chocolate attribute exhibited the same quality in both samples. The storage of the cocoa substitute sample for 6 months gave rise to an increase in the chocolate attribute. The other attributes showed opposite behaviour. The headspace volatiles of both real cocoa and cocoa substitute were isolated and subjected to gas chromatography (GC) and gas chromatography–mass spectrometric (GC–MS) analysis. Most of the volatile compounds identified in real cocoa especially the key odorants were represented in the cocoa substitute sample. The two compounds, 2-phenyl-2-butenal and 5-methyl-2-phenyl-2-hex-2-enals, that are important contributors to chocolate aroma, showed noticeable increase after storage of cocoa substitute sample for 6 months.     

牛肉真空滚揉条件对白卤牛肉品质和出成率的影响

为探讨真空滚揉技术在卤牛肉加工中的应用,论文分析了牛肉真空滚揉时真空度、转速、滚揉时间、载荷量、原料初始温度和静腌时间对白卤牛肉主要成分、感官品质、色度、质构特性及出成率的影响。将初始温度为0～5℃的牛肉、3.3%食盐和0.1%花椒放入滚揉器中,载荷量60%,真空度6 kPa,4 r/min滚揉15 min,静置10 min;加入1.3%洋葱汁、1.2%香芹汁、2.5%胡萝卜汁和1.8%二锅头,重复滚揉1次;出料后0～5℃静腌12h。采用上述操作条件腌制的牛肉加工的白卤牛肉的品质和出成率均较高。     

密封带在真空洗浆机中的应用

国内传统的真空洗浆机洗鼓与水腿之间通过分配头来连接,在使用过程中经常会发生漏气现象,而且维修也不方便。镇江金河纸业有限公司于1996年引进美国IMPCO公司的50m2CORU-DEK四型真空洗浆机,不仅能改善浆的洗涤效果,提高黑液提取率,减少流失,而且在真空系统中使用了新的部件——密封带。密封带不仅更换和维修方便,而且密封性能也相当好。在不采用强制真空的情况下,能达到比较高的真空度,洗浆质量也能得到保证。     

Comparative study of virgin olive oil sensory defects

The main sensory defects found in virgin olive oil (winey–vinegary, mustiness–humidity, fusty and rancid) were studied by dynamic headspace high-resolution gas chromatography with flame ionisation and mass spectrometry detection and dynamic headspace high-resolution gas chromatography–olfactometry to determine the most prominent volatile compounds responsible for them. A comparative study between defective and high quality virgin olive oils showed qualitative and quantitative differences in the volatile profiles, explained by the presence of enzymatic activities before the oil extraction process or by alteration during olive oil storage. The highest sensory significance, evaluated by odour activity values, corresponded to 1-octen-3-ol for mustiness–humidity, ethyl butanoate, propanoic and butanoic acids for fusty sensory defect, acetic acid, 3-methyl butanol and ethyl acetate for winey–vinegary and several saturated and unsaturated aldehydes and acids for rancid sensory defect.     

Effect of olive collection regime on olive oil quality

The titratable acidity and the peroxide value of olive oil extracted from olives harvested by shaking the trees over subtented nets increase rapidly as the residence of the fruit on the nets is prolonged. It is recommended that the extraction of the oil from the fruits is not delayed for longer than 2 to 3 weeks.     

Relations between compositional traits and sensory qualities of French dry-cured ham

The left hams of 20 pig carcasses were processed by dry-curing for either 179 (n = 10) or 273 days (n = 10). The Biceps femoris was taken at the end of the processing and submitted to chemical and sensory analyses. The following chemical traits were determined: pH, moisture, salt content, fatty acid content and composition of lipid classes (triglycerides, phospholipids, free fatty acids), nitrogen fractions (soluble and insoluble protein, non-protein nitrogen, free amino acids) and volatile compounds. Sensory analysis was performed by a panel of 12 trained members, who scored texture traits (firmness, dryness, fibrousness, mellowness), taste (salty, acid), intensity of aromas (typical of dry ham, fresh meat, fat, cured meat, rancid, metal), persistence of dry ham aroma, persistence of taste after deglutition, persistence of astringency, persistence of metallic taste. The sensory qualities of dry-cured ham showed noticeable changes between days 179 and 273. Firmness, dryness and intensities of aromas typical of dry-cured ham and cured meat were enhanced with time. Neither pH, moisture nor salt content played a noticeable role in determining the sensory quality of dry-cured ham. Among the volatile compounds, the levels of several ketones and 1-butanol were significantly correlated with the aromas of dry ham and cured meat, while rancid aroma was related to aldehydes, ethylacetate, 2,3-pentanedione and nonane. Therefore, the aromas of dry ham and cured meat appeared to be determined mainly by the products of lipid oxidation. However, they were related also to unidentified volatile compounds, whose identification would be of particular interest.     

真空干燥-常压缓苏后稻米品质指标的相关性研究

以不同干燥温度、相对真空度为因素对稻谷进行真空干燥-常压缓苏实验,研究其干燥后稻米爆腰增率、整精米率及蒸煮质构品质变化,分析其相关性,并通过扫描电镜观察不同干燥条件对稻谷籽粒显微形态的影响。结果表明:干燥温度和真空度对稻谷干燥后爆腰增率及整精米率影响极显著(p0.01)。干燥温度、真空度且二者交互作用对米饭质构特性有极显著影响(p0.01)。经过对稻谷干燥后各品质相关性分析,得出稻谷爆腰增率与其蒸煮硬度、胶黏性及胶着性呈极显著的正相关性(p0.01),稻谷整精米率与硬度、胶黏性、胶着性呈极显著负相关性(p0.01),且二者均与弹性、咀嚼性及内聚性没有相关性。干燥温度越高,相对真空度越大,干燥速率越大,淀粉粒与蛋白质的结合度越小,结构越稀松,干燥裂纹越粗大,数量越多。     

Influence of filtration on volatile compounds and sensory profile of virgin olive oils

The influence of filtration through a hydrophilic cotton layer on volatile compounds, sensory characteristics and colour of two monovarietal oils was investigated in this study. Volatiles were evaluated using headspace solid-phase microextraction-gas chromatography. After the filtration of Bu?a oils only a slight increase in total alcohols was noticed. In filtered ?rna oils a significant decrease of total alcohols and slight changes in total aldehydes, total ketones and total C5 volatile compounds concentration were detected. No significant influence on the sensory scores of oils, but some slight changes in sensorial profiles were noted (slightly higher intensities of sensory characteristics apple and grass, and higher values of the lightness L^∗ in filtered samples). The results point to unequal filtration impact on different monovarietal oils and could be useful in developing targeted technologies for specific monovarietal oils quality improvement.     

Effect of crushing on olive paste and virgin olive oil minor components

The present study focuses on the influence of the olive crushing technique on the minor composition of olive pastes and their corresponding virgin olive oils since these compounds are strongly related to their quality and characteristics. Two different cultivars, Arbequina and Cornicabra—known for their different minor component composition—were processed at laboratory scale using hammer mills at various breakage forces and grid hole diameters, a blade cutter and a mortar. Crushing and kneading produce a profound change in the composition of the phenolic compounds in the olive paste and in the final oil. Hydroxytyrosol derivatives in virgin olive oil were most affected by the crushing conditions. The stronger the crushing conditions (i.e. hammer crushers using smaller grid holes and a higher rotation speed), the higher the phenolic content in both olive paste and oil in both varieties. Interestingly, the effect on volatile compounds of milder or stronger crushing conditions was opposite to that described for the phenolic compounds.