泡制型酸茶产品品质评定探讨

概述酸茶产品的创制、发展过程与加工工艺,探讨品质评定方法。酸茶产品作为直接入口的食品,在评价安全性时存在应以茶叶的限量指标还是以食品的限量指标作为参照标准的问题,长期食用的安全性还有待进一步研究。     

Physiochemical and Microbiological Quality of Lightly Processed Salmon (Salmo salar L.) Stored Under Modified Atmosphere

Low‐temperature cooking, such as sous vide, has become a favored method for processing seafood. For this method to be applicable for retail products, combinations with other processing steps are needed to keep the products safe and durable while maintaining high quality. The present experiments were designed to investigate the influence of low‐temperature treatment (40, 50, or 60 °C) in combination with various packaging technologies (modified atmosphere [MA] or soluble gas stabilization [SGS]) on both the microbial growth and the physiochemical quality. Salmon loins were either kept natural or inoculated with Listeria innocua prior to drying (16 to 18 hr) in either 100% CO₂ (SGS) or atmospheric air (MA packaging). All samples were sous vide treated, repackaged in MA, and stored at 4 °C for 24 days. The results showed shelf life to be significantly improved with the implementation of SGS, by prolonging the lag‐phase and slowing the growth rate of both naturally occurring and inoculated bacteria. Variations in packaging technology did not significantly influence any of the tested quality parameters, including drip loss, surface color, and texture. Growing consumer demand for lightly processed seafood products makes Listeria spp. an increasing problem. The present experiment, however, has shown that it is possible to lower processing temperatures to as little as 40 or 50 °C and still obtain inhibition of Listeria, but with improved chemical quality compared to traditional processing.     

Fermentation Quality Characteristics and Flavor Formation Changes During the Process of Pickled Wax Gourd in Eastern Zhejiang

Using pickled brine as samples of natural pickled wax gourd at different stages of 0, 5, 10, 15, and 20 d, respectively, pH value, reducing sugar content, number of lactic acid bacteria and total bacteria, as well as organic acid content and volatile components, were investigated in this study. As a consequence, the lactic acid and acetic acid concentration increased with the decreasing of pH and sugar exhaustion through the pickling process. A total of 60 kinds of volatile compounds were detected, including 12 alcohols, 6 acids, 11 aldehydes, 12 ketones, 4 esters, 6 silicones, and 9 other compounds. At the end of 20 days fermentation, the abundant volatile compounds were identified including alcohols (47.58%), acids (36.00%), and esters (5.94%), with the highest content of acetic acid (27.97%), followed by ethanol (23.69%). The contributions of these compositions were clarified by electronic nose technology method combined with principal components analysis.     

韩国泡菜制作过程中理化特性及微生物的变化

为研究韩国泡菜制作过程中品质的变化,测定其在腌制、发酵过程中一系列理化指标及微生物指标。结果表明：腌制过程中,水分含量由96.23%降低为91.34%;pH值略微下降至6.46,而总酸含量上升至2.91 g/kg;硬度降低了19.26%,降低至188 6 N;菌落总数、乳酸菌总数、酵母菌数量及大肠菌群略微上升。在发酵期间,水分含量持续降低,降至82.54%;pH值下降至3.87,而总酸含量上升至7.02 g/kg;硬度降低了68.08%至565 N;L*（亮度）值与a*（红度）值显著增加,而b*（黄度）值显著降低;菌落总数下降至3.3×102 CFU/g;乳酸菌总数达到1.3×107 CFU/g;酵母菌数量先上升后下降,最终降低为9.1×102 CFU/g;大肠菌群在第4天达到最大值93 MPN/g,随后迅速下降,低于3 MPN/g。     

发酵方式对牛蒡泡菜理化特性及微生物数量变化的影响

以新鲜牛蒡为原料研制牛蒡泡菜,对比研究自然干法发酵、自然湿法发酵、纯种干法发酵、纯种湿法发酵对发酵过程中牛蒡泡菜的理化特性和微生物数量变化的影响,并对其产品进行感官评价。结果显示：纯种湿法发酵与其它发酵方式相比,牛蒡泡菜的发酵速度较快,优势明显,亚硝酸盐含量在第10天时降到稳定值（0.53 mg/100 g）,其它3种发酵方式在第12天时达到稳定值,并且亚硝酸盐含量高于纯种湿法发酵;与其它方式相比,纯种湿法发酵牛蒡泡菜乳酸菌数稍高,总糖和还原糖含量、大肠菌群数以及pH值较低;纯种湿法发酵牛蒡泡菜感官评分和脆度均高于其他3种发酵方式,纯种湿法发酵牛蒡泡菜感官评分为92.43,脆度为2 005.02 g;自然湿法发酵和纯种湿法发酵牛蒡泡菜产品的氨基酸态氮含量较自然干法发酵和纯种干法发酵低。综合比较各项指标,纯种湿法发酵为牛蒡泡菜的最佳发酵方式。     

发酵方式对山药泡菜理化特性及微生物变化的影响

对比研究山药自然发酵、混料自然发酵、山药接种发酵、混料接种发酵等4 种发酵方式对山药泡菜理化指标和微生物数量动态变化的影响,并对其感官品质进行评价。结果显示：接种发酵泡菜与自然发酵泡菜的发酵周期分别为11 d和14 d;与自然发酵泡菜相比,接种发酵山药泡菜的pH值下降快、总酸含量高、亚硝酸盐含量低,乳酸菌数量多、菌落总数和大肠菌群数少,但其脆度与感官评分偏低;混料发酵山药泡菜口味纯正、品质优良,pH值为3,总酸含量为8.01 mg/kg。其中混料自然发酵亚硝酸盐含量1.4 mg/kg、乳酸菌数7.33（lg（CFU/mL））、菌落总数3.2（lg（CFU/mL））、大肠菌群数15 MPN/100 g、脆度2 975.00 g、感官评分89.10;混料接种发酵产品的亚硝酸盐含量1.2 mg/kg、乳酸菌数9.04（lg（CFU/mL））、菌落总数2.1 （lg（CFU/mL））、大肠菌群数6 MPN/100 g、脆度2 765.00 g、感官评分86.26。     

发酵剂对泡萝卜品质的影响

为确定不同发酵剂对泡萝卜品质的影响,将6 种不同微生物群落组成的发酵剂接种泡萝卜7 d,分析发酵过程中基本理化指标、质构特性、亚硝酸盐、17 种氨基酸和有机酸含量的变化。结果表明,接种发酵剂2的泡萝卜品质最佳,在接种第4天即可达到成熟。发酵至第7天,发酵剂3接种泡萝卜硬度略高于其他组（P＞0.05）,且发酵过程中亚硝酸盐含量远低于国家限量卫生标准。发酵过程中,泡萝卜所含氨基酸、有机酸种类丰富,其中接种发酵剂2泡萝卜在发酵7 d甜味和鲜味氨基酸显著高于其他组（P＜0.05）,谷氨酸含量最高,为（0.18±0.01）mg/g,有机酸含量也显著高于其他组（P＜0.05）,给予泡萝卜良好的风味品质。综合分析,发酵剂2能为高品质泡萝卜专用发酵剂的开发提供理论依据。     

不同发酵方式对木瓜泡菜品质的影响

以木瓜为原料,采用自然发酵法、乳酸菌发酵法(1%乳酸菌发酵、2%乳酸菌发酵)制作泡菜,分析不同发酵方式对木瓜泡菜pH值、可滴定酸、维生素C、质构动态变化和感官的影响。结果表明:2%乳酸菌接种发酵使得木瓜泡菜的pH值降幅更快,维持较高的可滴定酸含量,维生素C损失较少,硬度、胶黏性、咀嚼性最好。与自然发酵相比,添加乳酸菌发酵明显能缩短发酵周期,对营养和质构的保持较好,而且木瓜的香气浓郁,口感酸爽,质地脆嫩,整体感官最佳。     

超高压灭菌处理对酱腌菜品质的影响

为了探求超高压灭菌在酱腌菜工业中的应用,提高安全性,以酱腌菜为供试材料,通过单因素及正交试验法研究了酱腌菜的操作压强、加压时间、单位处理量对超高压灭菌效果的影响,并研究了超高压处理对酱腌菜品质的影响。试验结果表明:各因素对超高压灭菌效果的影响为:压强加压时间单位处理量,得出了操作压强为500 MPa、加压时间为20 min和单位处理量为200 g的最优组合。同时采用这个组合对样品进行超高压灭菌处理与不进行灭菌处理的进行对照,在相同的贮藏(恒温37℃)条件下,通过对不同的贮藏时间的酱腌菜进行理化指标检测和感官评价。结果得出对照组样品在贮藏20 d后已经腐败变质。经过超高压灭菌处理的样品60 d后酱腌菜内总酸、食盐、还原糖、亚硝酸盐、氨基酸态氮理化指标均符合酱腌菜卫生标准,大肠菌群数量≤30(MPN/100 g),并且色泽鲜亮,组织脆嫩,滋气味良好,感官评分达到70分。由此可知,超高压灭菌处理能够保持了酱腌菜的色、香、味和营养元素,并且延长酱腌菜的保质期和货架期。     

泡菜加工质量的影响因素及其发展趋势

系统介绍了泡菜的有益成分及影响加工质量的因素,并对泡菜产业的发展趋势进行了探讨。     

Microbiological and Color Quality Changes of Channel Catfish Frame Mince During Chilled and Frozen Storage

Microbial counts and color values of channel catfish frame mince were determined during storage at -20, 0, and 5 °C. Aerobic plate counts increased from 5.5 to greater than 8 log10 CFU/g by 3 d at 0 and 5 °C. Total coliform counts increased 1 log during refrigerated storage for 5 d. Both microbial populations declined during 3 mo frozen storage. Washed mince was lighter in color, less red, and less yellow than unwashed mince. Color of both mince types did not change during storage. Microbial results suggested that prepared catfish frame mince should be stored no longer than 3 d at 0 to 5 °C. Frozen mince remained acceptable for at least 3 mo at 20 °C. Key Words: catfish, mince, quality, microorganisms, color     

发酵时间对泡猪耳朵品质的影响

本试验以猪耳朵为原料,以四川泡菜的传统工艺进行加工泡猪耳朵,研究了加工过程中发酵时间对产品品质的影响。结果表明:发酵时间为23～35h时,产品可获得理想的pH值(3.4-3.6)和感官评分;经过真空包装和100℃加热杀菌,产品贮藏期可以达到30天以上。发酵时间对泡猪耳的风味影响显著(p<0.05),但对产品储藏期没有影响。     

Improvement in the Microbiological Quality of Ready-To-Use Desalted Cod

ABSTRACT: To reduce the microbial load of ready-to-use desalted cod, 2 different concentrations of sodium chloride (3.13% and 5.78% in water phase), potassium sorbate (0.14% and 0.20% in water phase), and citric acid (pH 6.10 and 5.77), with 2 kinds of packaging procedures (air or vacuum), have been used. The vacuum packaging was effective only in the samples with 3.13% salt after 28 d of storage, whereas no important differences between both packaging procedures were observed in samples with 5.78% salt. This last salt level only limited the Pseudomonas growth, however it was necessary to combine this salt concentration with potassium sorbate plus citric acid to inhibit mesophilic, psychrotrophic, and molds and yeasts.     

不同品种泡辣椒对特色川菜泡椒猪肝感官品质的影响

泡辣椒具有制作简单,增进食欲,增强菜肴风味的作用,是四川常用的一种调味料.文章分别选择了川菜制作中5种常用的泡辣椒品种,用于制作传统川菜泡椒猪肝.采用层次分析法进行权重分配,通过模糊数学法对5种菜品的感官质量进行了综合评定.结果 表明,不同品种的泡辣椒对泡椒猪肝感官品质的影响各异,添加了二荆条的菜品感官评分最高,添加了...     

杀菌方式对低盐腌渍黄瓜的品质影响

为了探讨不同杀菌方式对低盐腌渍黄瓜保脆效果及品质的影响,以广西地区所产的低盐腌渍黄瓜为原料,对比分析巴氏杀菌、微波杀菌和臭氧杀菌3种杀菌方式对低盐腌渍黄瓜的菌落总数、硬度、色差、亚硝酸盐、氯化钠、总酸、总糖、V_C及感官评价等指标的影响。结果表明,保证低盐腌渍黄瓜在90 d内不胀袋且硬度较好的最佳杀菌条件为巴氏杀菌85 ℃ 15 min,微波杀菌650 W 150 s,臭氧杀菌50 mg/m³ 40 min。其中臭氧杀菌对低盐腌渍黄瓜的硬度、色泽、总酸和总糖影响较小;其硬度为295.75 g,亚硝酸盐含量最低,为0.31 mg/kg;V_C含量、感官评分最高,分别为0.11 g/100 g、90.45分。因此,臭氧技术不仅有良好的杀菌效果,而且能保持低盐腌渍黄瓜的品质,在工业化杀菌上有一定的应用潜力。     

微生物发酵对蔬菜腌制品品质的影响

本文综述了蔬菜腌制过程中微生物的发酵作用的类型,主要探讨了乳酸发酵作用、酒精发酵作用和醋酸发酵作用对成品品质的影响。     

Microbiological Changes in Fresh Market Tomatoes During Packing Operations

Preliminary studies in two fresh market tomato packing houses in the Charleston, SC area showed significant differences in microbial counts on tomatoes by packing house, sampling point in packing lines, and season. Higher total plate counts, Enterobacteriaceae counts, and mold counts were found in one packing house, probably due to a failure to maintain adequate chlorine in the wash water. Total plate and Enterobacteriaceae counts were higher on tomatoes packed in July than in November. Enterobacteriaceae and molds isolated from the tomato samples were those normally associated with soil-borne contamination. Enterobacter agglomerans, Enterobacter cloacae, and Serratia marcescens were predominant Enterobacteriaceae identified; Alternaria, Penicillium, and Cladosporium were the predominant molds isolated and identified.     

不同保鲜包装方式对菜心品质的影响

为了考察不同保鲜包装方式对菜心品质的影响,采用厨房纸巾包装（ZJ）、普通塑料保鲜袋（CPE）、气调保鲜袋（EFB、JG）保鲜菜心,以不做任何保鲜处理的菜心为对照（CK）,分别在常温（18～23 ℃）和低温（4～6 ℃）下贮藏5和25 d,评价菜心的外观商品性、腐烂率、黄化率、失重率、叶绿素、水分、可溶性糖和维生素C含量的变化。结果表明:气调保鲜袋（EFB、JG）包装的保鲜效果优于CPE和CK,ZJ最差。较于其它包装方式,EFB和JG处理的菜心外观商品性更高,保持较高的营养品质。其中JG对菜心保鲜效果最佳,低温贮藏25 d时腐烂率为0.03%,黄化率为0.42%,失重率为1.55%,叶绿素含量降低幅度为5.01%,水分下降幅度为1.26%;低温贮藏15 d时,可溶性糖含量与第1 d无显著差异（P>0.05）,维生素C含量降低幅度为11.43%,显著低于其它包装处理（P<0.05）。综上,低温配合气调保鲜袋贮藏能延长菜心保鲜期,是一种较好的菜心贮藏保鲜方法。