延边黄牛发酵牛肉干在贮藏期间颜色及氧化稳定性的研究

对发酵牛肉干与传统牛肉干在贮藏期间表面颜色和氧化稳定性进行了研究.发酵牛肉干分别用泡菜汁、乳酸菌菌种发酵液对原料肉进行发酵制作而成.然后将三种牛肉干真空包装后放入4℃冰箱中贮藏6个月,每个月对其pH、TBA值、颜色进行测定.结果表明:泡菜汁发酵牛肉干的CIE a*值在贮藏期间没有显著性变化(P>0.05),经发酵的牛肉干在贮藏期间的TBA值显著低于传统牛肉干(P<0.05).     

延边黄牛发酵牛肉干在贮藏期间颜色及氧化稳定性的研究

对发酵牛肉干与传统牛肉干在贮藏期间表面颜色和氧化稳定性进行了研究。发酵牛肉干分别用泡菜汁、乳酸菌菌种发酵液对原料肉进行发酵制作而成。然后将三种牛肉干真空包装后放入4℃冰箱中贮藏6个月,每个月对其pH、TBA值、颜色进行测定。结果表明:泡菜汁发酵牛肉干的CIE a*值在贮藏期间没有显著性变化(P>0.05),经发酵的牛肉干在贮藏期间的TBA值显著低于传统牛肉干(P<0.05)。      

延(边)黄牛泡菜发酵牛肉干的研制

以延(边)黄牛米龙肉为原料,泡菜汁为发酵液对发酵牛肉干进行研究。先通过单因素试验确定食盐、葡萄糖、泡菜汁、亚硝酸钠的添加量,再通过正交实验对泡菜发酵牛肉干的最佳配方进行了优化。试验结果表明,发酵牛肉干最佳配方为食盐添加量为1.5%,葡萄糖添加量为3%,泡菜汁添加量为25%,亚硝酸钠添加量0.015%。     

泡菜发酵牛肉干与传统牛肉干贮藏期间颜色及氧化稳定性的研究

本实验对泡菜发酵牛肉干与传统牛肉干在贮藏期间表面颜色和氧化稳定性进行了研究.泡菜发酵牛肉干是以延(边)黄牛米龙肉为原料,泡菜汁为发酵液制作而成.然后将两种牛肉干自封袋包装后放入4℃冰箱中贮藏6个月,每个月对其pH值、TBARS值、颜色进行测定.结果表明:贮藏期间泡菜发酵牛肉干的CIE a*值显著低于传统牛肉干(P&;lt;0.05),泡菜发酵牛肉干在贮藏期间的TBARS值显著低于传统牛肉干(P&;lt;0.05).     

乳酸菌对发酵牛肉干品质影响的研究

选择发酵肉制品中常见的4株乳酸菌,将其应用于发酵牛肉干中,研究菌株对于产品理化和微生物指标的影响,结果表明:清酒乳杆菌的产酸能力最强,能在发酵初期迅速降低产品的pH值,并使pH值始终维持在较低水平,有效抑制致病菌的生长,降低产品的水分活度,但最终产品酸味较重;发酵乳杆菌产酸能力弱,不利于产品的安全性;植物乳杆菌和干酪乳杆菌适合发酵牛肉干的生产,其中植物乳杆菌发酵组颜色好于干酪乳杆菌,而干酪乳杆菌在风味上得分高于植物乳杆菌。     

直投式发酵剂对发酵牛肉干品质的影响

将干酪乳杆菌和木糖葡萄球菌按一定比例混合制备直投式复合发酵剂,再将其应用于发酵牛肉干,研究其对牛肉干发酵过程中理化指标和微生物特性的影响。试验被分为自然发酵对照组、普通发酵剂组和直投式发酵剂组。研究结果表明:添加普通发酵剂和直投式发酵剂均可降低牛肉干的p H,且显著低于自然发酵组(P0.05);3组牛肉干的水分含量、水分活度和红度值之间无显著差异(P0.05);添加发酵剂的牛肉干的乳酸菌总数、葡萄球菌总数和细菌总数较自然发酵组高(P0.05),感官品质较好(P0.05),这说明直投式发酵剂具有良好的发酵活力,能够提高发酵牛肉干的品质,缩短发酵时间。     

发酵型酸汤味牛肉干的发酵工艺研究及品质分析

以感官评分为评价指标,研究不同复合发酵剂添加量、发酵温度、发酵时间对发酵型酸汤味牛肉干品质的影响。结果表明,最佳发酵工艺条件为复合发酵剂（乳酸菌∶酵母菌=3∶1）添加量为2.2%,酸汤添加量为8%,蜂蜜添加量为10%,食盐添加量为1%;30 ℃发酵21 h。在此优化条件下,发酵型酸汤味牛肉干出品率42.22%,亚硝酸盐含量0.02 mg/kg,水分含量35.30 g/100 g,脂肪含量19.88 g/100 g,蛋白质含量36.31 g/100 g,pH值为5.21,总糖含量8.07 g/100 g。发酵型酸汤味牛肉干的质量指标符合牛肉干相关标准要求,比自然发酵酸汤味牛肉干的品质好。     

复合发酵剂对发酵牛肉干理化品质及安全性能的影响

以清酒乳杆菌、戊糖片球菌及木糖葡萄球菌为复合发酵剂(1:2:2)制作发酵牛肉干,通过色差计及高效液相等仪器测定不同阶段牛肉干的pH、水分活度、色泽及生物胺含量等指标的变化,旨在探究复合发酵剂对发酵牛肉干理化品质和生物胺组成的影响.结果表明:接种上述复合发酵剂促使肉干中乳酸菌快速成为优势菌群,加快产品酸化速率,发酵结束时...     

发酵时间对半干型发酵牛肉干品质及蛋白质构象的影响

通过接种沙克乳杆菌为发酵菌株对半干型牛肉干进行发酵,研究不同发酵时间的半干型发酵牛肉干品质与蛋白质构象。基于对半干型发酵牛肉干水分含量、水分分布、pH值、水分活度、剪切力、感官评价指标的测定,结合电子鼻10 个传感器信号数据的主成分分析研究其品质差异。采用拉曼光谱技术研究发酵时间对半干型发酵牛肉干蛋白质构象的影响。结果表明,pH值与水分活度随着发酵时间的延长而降低,在发酵60 h时达到最低。剪切力在发酵过程中先降低、后增加,在24 h达到最低。水分含量在发酵过程中先降低后逐渐稳定。发酵后产品的不易流动水减少,结合水增加。感官评价表明,发酵36 h的半干型牛肉干色泽、风味、咀嚼性评分以及感官总分均显著高于其他组。电子鼻分析得出,发酵可产生酯类、醇类等挥发性化合物,赋予产品特殊的风味。通过对拉曼光谱进行分析,发现发酵48 h的α-螺旋与t-g-t构象相对含量均为最低,发酵后产品蛋白质稳定性下降。因此,沙克乳杆菌可作为半干型发酵牛肉干的发酵剂,最适发酵时间为24～48 h。     

发酵型牛肉干发酵体系与产品品质特性相关性研究

通过四种自然发酵液的配比正交试验,筛选出最佳发酵液的组合,同时对发酵前后原料肉营养组分及发酵体系代谢产物进行了动态分析、测定。结果表明,发酵过程中物质消长规律与产品品质有关,经过发酵处理的牛肉具有显著的组织学结构变化特征。     

CHANGES IN QUALITY OF DEHYDRATED KIBBLED ONIONS DURING STORAGE

SUMMARY— Dehydrated kibbled onions. of the Egyptian variety, containing 4-5% moisture, were stored under different conditions and their keeping quality as influenced by storage variables determined. 3 packaging materials, namely cans, polyethylene and Saran pouches were used. Samples were stored at temperatures of 15, 25 and 35°C at 44% relative humidity for 39 wk. Temperature of storage was found to have the largest effect on product quality. The can package was found to be superior to the flexible pouches; however, Saran pouches could be used under certain conditions. Moisture content increased significantly in polyethylene pouches at all temperatures, but in Saran pouches only at 25° C Absorbance of onion extracts, as measure of browning, increased significantly with storage temperature and to a smaller extent due to packaging materials. Products in polyethylene deteriorated most, while the difference between Saran- and can-packed products was small. A similar trend in results was found in tristimulus color determinations. All products stored at 15° C and those in cans at 25°C were found to be of good organoleptic quality. The pyruvic acid development potential could not be used as a sensitive indicator for determination of product quality.     

番茄粉在贮藏过程中品质稳定性的研究

随机抽取5批番茄粉至温度为20℃以下,湿度为60%以下条件下贮藏8个月,定期观察和测定其物理性状和部分理化指标的变化情况.结果表明,随贮藏时间的延长,番茄粉感官无异常变化,番茄红素较最初下降18.26%,总酸增加3.26%.各项微生物指标均符合国标限量标准.     

STORAGE QUALITY OF MINIMALLY PROCESSED CABBAGE PACKAGED IN PLASTIC FILMS

The effects of packaging and storage at 3C in a refrigerated case on quality changes of minimally processed cabbage were studied. Shredded cabbage samples were packaged in three forms: bags of monooriented polypropylene film (OPP bags) and polyethylene trays overwrapped with a multilayer polyolefin (RD106-PE tray) or with a plasticized PVC film (PVC-PE tray). All types of package effectively controlled the weight loss. The modified atmosphere in PVC-and RD106- PE trays did not change more than 3% as compared with normal atmosphere levels. However, in OPP bags, O₂ reached 2% and CO₂ increased to approximately 13% after 3 days. The microbiological quality during the storage period for all types of packaging was satisfactory. OPP samples were significantly better (p <0.05) in general appearance, wilting and browning but developed an off-odor. No off-odor was detected in samples packaged in PVC and RD106-PE trays. Shelf life for the three packaging forms was estimated.     

EVALUATION OF TIME-TEMPERATURE RELATED QUALITY CHANGES IN ICE CREAM DURING STORAGE

The keeping quality of vanilla-flavored ice cream was investigated during 21 weeks of storage. Ice cream samples at 4 different temperature treatments were evaluated for 3 attributes by 14 judges using a deviation-from-reference scale. Sampling tools and presentation containers were designed to provide uniform samples and serving temperatures without melting. The ice cream kept at a variable storage treatment showed a trend toward becoming less firm and darker in yellow than the other samples from the 86th day of storage onward. Differences in creaminess, hardness, and vanilla flavor were noticed in ice cream after 170 days of storage. A commercial time-temperature indicator was used to monitor temperature exposure; but, since indicator response was slower than published, no correlations could be made with quality changes.     

A RESEARCH NOTE: SENSORY QUALITY CHANGES OF HIGH MOISTURE PINEAPPLE BITS DURING STORAGE

Minimally processed high moisture pineapple bits prepared in sucrose syrups, in order to decrease water activity to 0.92, 0.95 and 0.97, were stored at 30, 35 and 40C and evaluated by selected and trained sensory panelists using the Karlsrühe Quality Test. Color, flavor and texture changes were significantly lower for the 0.92 a_w product stored at 30C. It can be predicted by shelf‐life estimation that this product will maintain a satisfactory sensorial and microbiological quality for up to 50 days.     

芹菜汁酸豆奶的研制

探讨了芹菜汁酸豆奶的工艺,并采用正交试验确定芹菜汁酸豆奶的最佳发酵条件,结果为：保加利亚乳杆菌（Lactobacillus bulgaricus）嗜热链球菌（Streptococcus thermophilus）=1：1,接种量为4%,芹菜汁添加量为10%,脱脂乳粉的添加量10%,发酵温度40℃,发酵时间5h.     

山茱萸酒发酵工艺研究

以山茱萸干果肉为原料,经葡萄酒高活性干酵母发酵生产山茱萸保健果酒,并采用无机陶瓷膜对产品进行澄清过滤和杀菌;在正常发酵下,以保健果酒中马钱素和熊果酸两种功能性成分及一些理化指标为依据,确定山茱萸酒发酵最佳工艺条件为:料液比1∶10,酵母接种量0.2%,温度20℃～25℃,果胶酶添加量0.02%,SO2添加量50mg/L.     

QUALITY CONTROL CHARTS FOR STORAGE OF EGGS

Modified Shewhart charts were constructed with weight loss, Haugh units and yolk index for storage of untreated, soda lime, water glass or oil coated and thermostabilized eggs. The data obtained showed differences between the treatments, and control charts derived therefrom illustrate maintenance within limits of the inevitable quality loss which accompanies storage of eggs. Knowledge of the trends make it possible to readjust the storage conditions to prolong the period before violation of acceptable limits comes into play.