Effect of Postmortem Storage on Titin and Nebulin in Pork and Poultry Light and Dark Muscles

Purified myofibrils were prepared from samples of chicken breast and thigh muscles and from light and dark portions of pork semitendinosus muscle at death and after storage at 4° and 22°C for 1, 3, and 7 days postmortem. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) was used to examine the effect of postmortem storage of muscle on titin and nebulin. Results indicated that titin and nebulin were more rapidly degraded in light than in dark chicken muscle. In contrast, titin and nebulin were more rapidly degraded in dark than in light pork muscle.     

3种添加剂对油炸薯片丙烯酰胺产生和质构的影响

在前期研究基础上,探讨了3种添加剂NaHSO3、CaCl2和半胱氨酸浸泡土豆片对油炸薯片中丙烯酰胺形成的抑制作用,同时采用白度仪和质构仪测定了油炸薯片的白度和脆度,发现半胱氨酸和CaCl2能有效地抑制丙烯酰胺形成且对薯片色泽和脆度影响较小,是两种具有应用前景的丙烯酰胺抑制剂。     

淡爽型啤酒生产技术的研究

以麦芽、大米、酒花为原料 ,对不同比例的麦芽用量作了小试 ,认为用45 %较55%为佳 ;辅料大米以37%为好 ,糖化pH5.2～5.4,糊化pH6.0～6.3,煮沸90min ,第一次加酒花2kg,第二次加酒花9kg,第三次加酒花7kg,接种酵母7.0‰ ,发酵最高温度12℃ ,最高压力0.12MPa,发酵第6天开始测双乙酰 ,当双乙酰降至0.8×10-7时 ,保温48h ,再以0.3℃/h降至0℃ ,后酵7天以上。成品酒理化指标达GB4929—91优级标准。     

1-甲基环丙烯对甘薯块根贮藏过程中品质相关指标的影响

以目前广泛栽培的4 个鲜食型甘薯品种为材料,研究了1-甲基环丙烯（1-methylcyclopropene,1-MCP）对贮藏过程中甘薯块根品质相关指标的影响。结果表明,1.00 μL/L的1-MCP对甘薯块根中可溶性糖、直链淀粉、支链淀粉以及胡萝卜素含量等甘薯品质相关指标有显著影响,并且这种影响因甘薯品种不同而存在明显差异。与对照处理相比,1-MCP处理的4 个甘薯品种可溶性糖含量达到高峰值的时间均有所提前,1-MCP显著提高了‘广87’和‘烟薯25’块根中可溶性糖含量峰值。1-MCP显著降低了0～7 d贮藏期间‘广87’、‘烟薯25’和‘龙薯9号’块根中直链淀粉含量,显著提高‘广87’和‘苏薯16’贮藏期间直链淀粉含量峰值,显著降低了‘苏薯16’和‘烟薯25’在贮藏28～120 d期间块根中直链淀粉含量。1-MCP还显著降低了‘苏薯16’和‘龙薯9号’在贮藏28～120 d期间的支链淀粉含量。1-MCP也显著改变了胡萝卜素含量的变化趋势,提前了‘广87’、‘苏薯16’和‘龙薯9号’在贮藏期间胡萝卜素含量达到最低值的时间。     

Effect of Herbicides on Chemical Composition of Potato Tubers and Quality of the Subsequent Chips and Starch

Application of 6 different herbicides in potato cultivation resulted in changes of chemical composition of tubers, quality of chips and properties of starch. Sencor, Bladex, Topogard, Afalon and Aresin indicated rather unfavourable effects on chemical composition of the tubers. On one hand they increased the average weight of the tubers, on the other hand they decreased the dry matter (triazines) and starch content (Afalon). They increased the amount of reducing and total sugars (urea) and increased the content of amide nitrogen (triazines and Afalon) and amino acid nitrogen (Bladex). Sencor and Afalon resulted in darker colour of the chips. Afalon, Aresin and Chwastox increased the part of small granules or decreased the amount of large granules in the starch. Afalon and Bladex resulted in changes of phosphorus content, and Chwastox changed the amount of amylose in starch.     

造粒对芝麻盐贮藏稳定性、风味的影响及其货架期预测模型的建立

通过造粒加工,开发出造粒芝麻盐,以期延长芝麻盐货架期,延缓风味衰减。采用加速试验方法,探究造粒芝麻盐和传统芝麻盐在不同温度下的贮藏稳定性,进而构建货架期预测模型,评估造粒延长芝麻盐货架期的效果,同时采用气相色谱-质谱法(GC-MS)对比分析贮藏过程中风味物质变化。结果表明:在贮藏过程中,造粒芝麻盐和传统芝麻盐的酸价和过氧化值均随温度升高而增大,同一温度条件下,二者酸价变化没有显著性差异(P>0.05),过氧化值变化显著(P<0.05)。在常温(25 ℃)储藏条件下,造粒芝麻盐货架期预测值为377 d,传统芝麻盐货架期预测值为211 d。造粒芝麻盐和传统芝麻盐风味物质在储藏过程中吡嗪类、烷类物质相对含量均呈明显降低趋势,醛类、呋喃类、醇类、酮类物质相对含量呈上升的趋势。随储藏时间的延长,传统芝麻盐油脂氧化产物酮类物质上升幅度远远大于造粒芝麻盐,对芝麻盐风味物质贡献较大的醛类物质来说,造粒芝麻盐相对含量要高于传统芝麻盐。因此,相对于传统芝麻盐来说,造粒可延缓产品氧化,大幅提高货架期,利于风味物质保留。     

Effect of Combined Gamma-Irradiation and Storage on Biochemical Changes in Sweet Potato

Sucrose of uncured Red Jewel sweet potato increased from 3.8% to 10.7% after a combined treatment of a 300 Krad dose and 4 days storage at 24°C post-irradiation (PI). Starch decreased from 16.8% to 6.1% after 16 days following a 500 Krad treatment. Phosphorylase, phosphoglucomutase and sucrose phosphate synthase enzyme specific activities increased 2.4-, 1.8- and 1.3-fold, respectively, after 3 days PI following 200 Krad exposures compared to nonirradiated roots. The beta-Amylase, phosphoglucose isomerase and sucrose synthase specific activities increased 1.2-fold. Sucrose synthesis in the irradiated sweet potato was attributed to beta-amylase, phosphorylase, phosphoglucomutase, phosphoglucose isomerase and sucrose synthase.     

Effect of Low-Pressure Plasma Exposure on the Storage Characteristics of Brown Rice

Food and Bioprocess Technology - In the present study, the use of nonthermal plasma for the treatment of brown rice was pioneered with the aim to maintain the quality during storage and its...     

不同气体比例对金枪鱼气调解冻及贮藏期间保鲜效果的影响

为减缓解冻过程及解冻后金枪鱼品质劣化,研究金枪鱼在不同气体比例条件下解冻及后续贮藏期间的品质变化。采用6种不同气体比例(100%O_2、20%O_2+80%N_2、60%O_2+40%N_2、40%O_2+60%CO_2、20%O_2+60%CO_2+20%N_2、40%O_2+40%CO_2+20%N_2),在4℃冷藏条件下对金枪鱼进行解冻及贮藏,以汁液流失率、pH值、色泽、嫩度、硫代巴比妥酸反应物值、高铁肌红蛋白含量、挥发性盐基氮、菌落总数等理化指标的变化为依据评价金枪鱼的品质变化。结果表明:气调解冻对金枪鱼的色泽影响较明显,并且气调包装有利于金枪鱼贮藏期间的保鲜,其中组4(40%O_2+60%CO_2)金枪鱼气调解冻及贮藏期间保鲜效果最好。     

Effect of Sodium Salts and Added Water on Color of Dark Meat Turkey Patties Subjected to Long-term Storage

Patties from a Control (all meat), Treatment I (meat, 1.1% water, 1.0% NaCl and 0.5% STP) and Treatment II (meat, 11.1% water, 1.0% NaCl and 0.5% STP) were frozen for 0 to 24 wk, broiled, and analyzed for color attributes. Treated patties had lighter exterior surfaces with reduced redness and increased yellowness. The opposite effects were observed for the interior of patties. Treatment II had elevated values for internal yellowness as compared to Treatment I. Storage caused an increase in both external and internal color values. Sensory scores indicated that internal redness of treated patties was greater than that of the Control but gradually decreased during storage.     

Effect of Storage Temperature on Some Rehydrating Properties of Potato Granules

The Swelling Power (SP), Water Binding Capacity (WBC) and rate of rehydration of Add-Back (A–B) and Freeze-Thaw (F–T) potato granules treated with 0.2% monoglyceride decreased during the initial 14 weeks of storage by an average of 25.5 (F–T) and 27.3% (A–B) at 4°C and by 11.1 (F–T) and 12.0% (A–B) at 25°C. However, the moisture content showed an opposite trend, increasing by 5.9 (F–T) and 7.5% (A–B) at 4°C and by 3.6 (F–T) and 4.9% (A–B) at 25°C. Storage beyond 14 weeks at 4°C resulted in increases in SP, WBC and rate of rehydration and decreases in moisture content. However, such a trend was not observed at 25°C. The percentage decreases in SP (during the initial 14 weeks) of treated granules (A–B and F–T) were lower than those of untreated granules by an average of 11.0% at 4°C and 10.5% at 25°C. The extent of starch matrix-cell wall separation and the intensity of the “V” diffraction pattern of an X-ray analysis increased during storage, with greater increases being found at 4°C.     

生姜提取液对鲜切马铃薯贮藏品质的影响

为研究生姜提取液对延缓食品中营养成分损失的效果,考察提取剂浓度、料液比、超声功率、超声时间对鲜切马铃薯中粗蛋白、淀粉和粗纤维含量的影响,结合正交试验优化生姜提取液的最佳配制方案。结果表明：生姜提取液的最佳配制方案为料液比1∶15.0（g/mL）、提取剂浓度65%、超声功率500 W、超声时间15.0 min,在此条件下所得生姜提取液可最大程度减缓粗蛋白含量、粗纤维含量损失,延缓淀粉含量减少,能够较好地保留鲜切马铃薯的营养成分。     

超声辅助茶多酚处理对贮藏期鲜切马铃薯的护色作用研究

为研究超声波辅助茶多酚处理(ultrasound assisted tea polyphenols,US-TP)对鲜切马铃薯的护色作用,以未处理鲜切样品为对照组(CK),考察US-TP处理对贮藏期鲜切马铃薯褐变指数(browning index,BI),多酚氧化酶(polyphenol oxidase,PPO)、过氧化...     

光源对冷却肉贮藏期间保鲜效果的影响

以两个部位的冷却猪肉（猪背最长肌、猪后腿肉）为主要实验原料,研究粉色光、粉紫色光、紫外光等光源对冷却猪肉色泽、氧合肌红蛋白含量、硫代巴比妥酸（TBA）值及菌落总数的影响,旨在选出最利于冷却猪肉保鲜的光源种类。结果表明：冷藏期间,粉色光组下冷却猪肉的色泽评分、a*值、氧合肌红蛋白含量及这三个指标的总体下降率（分别为38.64%~40.00%、10.36%~13.61%、25.88%~34.98%）均明显高于避光组、粉紫色光组和紫外光组。与避光组、粉紫色光组和紫外光组相比,粉色光源更有利于冷却猪肉肉色的稳定,且在此光源下,肉样的脂类氧化程度（TBA值总体增加率41.38%~86.57%）较其他三组更低。建议冷却猪肉在实际售卖过程中,陈列展示柜中采用粉色光源,提高冷却猪肉的保鲜效果。     

马铃薯全粉对冷冻熟面冻藏品质的影响

将15%马铃薯生全粉和15%马铃薯熟全粉分别与小麦粉混合制作冷冻熟面,探究其在冻藏期间质构品质、蒸煮品质的变化,并通过核磁共振仪、傅里叶红外光谱仪等,研究两种马铃薯全粉对冷冻熟面中水分结合状态、淀粉分子短程有序性、麦谷蛋白大聚体含量和微观结构的影响。结果表明,添加15%马铃薯生全粉能够延缓冷冻熟面冻藏期间质构品质和蒸煮品质的下降,抑制紧密结合水向自由水迁移以及水分的散失,降低冷冻熟面老化速率,延缓麦谷蛋白大聚体解聚,面筋网络结构连续性较好。而添加15%马铃薯熟全粉的冷冻熟面在冻藏期间,蒸煮品质下降,拉断力和拉断距离显著降低,面筋网络结构的连续性遭到严重破坏,不适宜长期冻藏。因此,添加马铃薯生全粉有利于保持冷冻熟面冻藏期间的品质,延缓冻藏品质的劣变,延长冷冻熟面货架期。     

低温真空油炸工艺对小龙虾虾尾酥品质的影响

为丰富即食水产品种类,探索真空油炸技术,以单冻小龙虾虾尾为原料,通过低温真空油炸工艺制备小龙虾虾尾酥产品。在单因素试验的基础上,以水分、油脂含量、酥脆性、硬度、丙烯酰胺含量为指标,选择油炸温度、油炸时间、油料质量比和脱油时间为变量,利用正交试验设计对真空油炸工艺进行优化。结果表明,真空油炸工艺的最优条件：真空度0.09 MPa,油炸温度95℃、油炸时间120 min、油料质量比3.0:1.0、脱油时间25 min,此条件下,小龙虾虾尾酥水分含量为（2.65±0.11）%,粗脂肪含量为（25.66±1.88）%,硬度为（443.21±42.36）g,酥脆性与常压油炸小龙虾虾尾酥无显著差别,丙烯酰胺含量为（11.2±0.17）μg/kg。相比于常压油炸,低温真空油炸工艺不仅减少营养损失,而且降低了油脂及丙烯酰胺含量,为提升小龙虾油炸制品品质提供理论依据和科学指导。     

光照和温度对草鱼和三文鱼鱼肉贮藏品质的影响

采用4、10(无光照)、10(5 000 lx)、25℃条件,同时贮藏草鱼鱼片(除去红肉)和三文鱼鱼片,研究光照和温度对草鱼和三文鱼贮藏品质的影响。结果表明,草鱼和三文鱼贮藏过程中pH值、挥发性盐基氮(total volatile basic nitrogen,TVB-N)值、硫代巴比妥酸(thiobarbituric acid,TBA)值和色差变化差异显著(P0.05),且菌落总数(total viable count,TVC)、pH值、TVB-N值、TBA值、色差、ATP分解产物(adenosine triphosphate-related decomposition products)K值均随着贮藏时间的延长而增加。光照(5 000 lx)对于草鱼、三文鱼贮藏过程中的pH值变化、TBA值变化影响显著(P0.05),能使鱼肉中pH值增加量高于避光保存,促进光氧化,提高TBA值增加速率,而对于TVC、TVB-N值、K值、色差变化影响不显著(P0.05)。贮藏温度的差异(4、10℃)对两种鱼肉品质变化都有显著影响(P0.05)。     

茶多酚在油炸过程中对马铃薯片品质及其贮藏稳定性的影响

以感官品质、质构特性、理化特性、风味特性以及丙烯酰胺含量为指标,研究茶多酚在连续油炸过程中对马铃薯片品质的影响,并进一步探究茶多酚对马铃薯片贮藏稳定性的影响。结果表明,茶多酚对连续油炸过程中马铃薯片感官品质及硬度值的下降具有抑制作用;茶多酚对连续油炸过程中马铃薯片水分含量和含油率的增加具有明显的抑制作用,并且降低了薯片的含油率,茶多酚组T₂₄批次的马铃薯片含油率为41.96%±2.00%,显著低于空白组的46.29%±1.06%(P<0.05)。同时,与空白对照组相比,茶多酚抑制了马铃薯片劣变风味的产生,明显抑制了马铃薯片中有害物丙烯酰胺的生成。此外,茶多酚能够增加油炸马铃薯片的贮藏稳定性,平均货架期能够延长8 d。初步分析,茶多酚在油炸过程中对油脂品质的保护作用是其能够提高马铃薯片品质的重要原因。     

1- 甲基环丙烯对李果实冷藏及货架期非挥发性风味物质的影响

使用多变量分析方法研究1-MCP对‘黑琥珀’李果实0℃贮藏和随后的20℃货架期间非挥发性的糖、有机酸和氨基酸的影响。单因素试验结果表明：低温贮藏期间,李果实蔗糖和苹果酸含量逐渐下降,D-果糖含量先降后升,其余组分均在贮藏67d时达到释放高峰;货架期间,96d后的货架期非挥发性组分含量均达到高峰。主成分分析结果表明：与出库时相比,冷藏67d后的货架9d时各组分含量均降低,而贮藏后期的货架9d时则升高;冷藏67d时及冷藏96d后的货架期,1-MCP处理均显著降低了糖、酸类物质的峰值,减缓了糖、酸物质的代谢速率,维持了冷藏期间的营养品质并延缓了货架期的品质劣变。偏最小二乘和通径分析结果表明：D-果糖与感官甜酸比呈显著正相关,是主要的直接与间接因子;苹果酸对感官酸度和可溶性固形物(SSC)均有显著正相关性,且对SSC主要通过D -葡萄糖的间接效应来实现;山梨糖醇与pH值呈极显著负相关。