冷却肉低剂量辐照后的理化和感官特性变化

研究真空包装冷却猪肉经保鲜液处理和未经过保鲜液处理,再分别经1kGy、2kGy和3kGy低剂量辐照后的理化和感官特性变化,进而确定最佳的辐照处理方式以延长冷却猪肉的货架期。结果表明:经过2kGy辐照的处理组,在贮藏的过程中,鲜红色泽保持相对的稳定。冷却猪肉经过保鲜液处理 2kGy剂量辐照 冷藏(4±1℃),可以有效的延长冷却猪肉的货架期。     

电子束辐照对泥蚶杀菌保鲜效果的影响

目的：研究电子束辐照对泥蚶微生物数量及其感官质量的影响。方法：泥蚶经不同剂量电子束处理,测定辐照后及冷藏期间菌落总数、大肠菌群及其感官评分。结果：电子束辐照能有效地杀灭泥蚶中的微生物,经过0、1、3、5、7、9kGy 不同剂量处理,泥蚶的菌落总数逐步下降,当泥蚶的初始菌落总数为3.10 × 105CFU/g时, D10=3.12kGy;泥蚶的感官质量与辐照剂量有关,经过7、9kGy 剂量处理后样品产生令人不愉快的异味。结论：结合辐照后及冷藏期泥蚶的微生物和感官指标,泥蚶电子束冷杀菌的适宜剂量为3～5kGy,经3～5kGy 处理后,泥蚶的货架期由对照组的5d 延长至15～19d。     

电子束辐照对小麦分离淀粉流变学特性的影响

从经过电子束辐照处理的小麦中提取淀粉,用Brabender连续粘度计研究不同辐照剂量（0、1.0、2.75、4.4kGy）对其流变学特性的影响,并用排阻液相色谱和多角度光散射仪、折光检测器连用技术（HPSEC-MALLS-RI）测定其分子量分布。结果表明:随着辐照剂量的增加,小麦淀粉的Brabender峰值黏度显著降低,冷稳定性升高,凝沉性减弱,当辐照剂量达到4.4kGy时,小麦淀粉的峰值黏度由85.0BU减小到42.0BU,下降了50.6%,回生值下降了88.2%;同时,小麦淀粉重均分子量逐渐下降,且当辐照剂量达到4.4kGy时,小麦淀粉的重均分子量与未辐照相比下降了1个数量级,说明电子束辐照引起了小麦中淀粉分子的降解,平均分子量减小,导致小麦淀粉流变学特性改变,粘度降低。      

电子束辐照对小麦分离淀粉流变学特性的影响

从经过电子束辐照处理的小麦中提取淀粉,用Brabender连续粘度计研究不同辐照剂量（0、1.0、2.75、4.4kGy）对其流变学特性的影响,并用排阻液相色谱和多角度光散射仪、折光检测器连用技术（HPSEC-MALLS-RI）测定其分子量分布。结果表明：随着辐照剂量的增加,小麦淀粉的Brabender峰值黏度显著降低,冷稳定性升高,凝沉性减弱,当辐照剂量达到4.4kGy时,小麦淀粉的峰值黏度由85.0BU减小到42.0BU,下降了50.6%,回生值下降了88.2%;同时,小麦淀粉重均分子量逐渐下降,且当辐照剂量达到4.4kGy时,小麦淀粉的重均分子量与未辐照相比下降了1个数量级,说明电子束辐照引起了小麦中淀粉分子的降解,平均分子量减小,导致小麦淀粉流变学特性改变,粘度降低。     

电子束辐照对新疆干果品质的影响及其最高耐受剂量的确定

目的 探究电子束辐照对4种新疆干果品质的影响,确定干果辐照工艺的最高耐受剂量。方法 采用0、2、4、6、8和10 kGy不同剂量电子束处理枸杞干、红枣干、无花果干、小白杏干,研究不同辐照剂量对水分、维生素C、总酸、总糖4种理化指标及色度、外观、风味、色泽和口感等5种感官品质的影响。结果 仅8 kGy辐照处理对枸杞干口感指标有不良影响,其他3种干果的感官指标几乎不受辐照处理的影响; 10 kGy以内的辐照处理对红枣干的品质无不良影响;无花果干的总酸含量在辐照剂量>6kGy时有所上升,维生素C含量在10 kGy处理时显著低于对照;辐照剂量≥6 kGy时,小白杏干维生素C含量显著降低。结论 通过对电子束辐照新疆干果的品质影响及最高耐受辐照剂量的研究,确定枸杞干、红枣干、无花果干和小白杏干的最高耐受剂量分别是8、10、6和6 kGy。为电子束辐照在新疆干果灭菌工艺中的应用提供了理论基础。     

速冻芦笋的电子束检疫杀菌和辐照工艺

为了研究电子束辐照处理对速冻芦笋检疫杀菌的工艺及效果,以速冻芦笋为试材,检测电子束辐照下金黄色葡萄球菌和出血性大肠杆菌的D10值,初始污染菌以及感官和营养品质变化。结果表明,接种菌悬液的速冻芦笋中,金黄色葡萄球菌、出血性大肠杆菌的D10值分别为0.35 kGy和0.25 kGy。经4.0 kGy辐照处理后,产品中菌落、霉菌、大肠菌群均未检出,感官指标未发生明显变化,营养品质仅维生素C含量下降稍快。产品的电子束穿透深度剂量分布试验表明,双面辐照工艺,辐照深度为14.2 cm时,不均匀度1.15,可以满足生产要求。建议采用4.0 kGy以下剂量辐照速冻芦笋产品,可以有效控制食源性致病菌,保障产品食用安全性。     

电子束辐照对沙拉酱微生物及品质的影响（网络首发、推荐阅读）

对市购沙拉酱用0、1、2 kGy不同剂量进行电子束辐照,研究电子束辐照对沙拉酱的杀菌效果及辐照后常温放置40 d后产品的微生物、色泽、质构、风味、稳定性等指标的变化,为沙拉酱物理冷杀菌的技术可行性和工艺设定提供技术参考依据。结果表明,电子束辐照对外源添加致病菌鼠伤寒沙门氏菌、大肠埃希氏菌、金黄色葡萄球菌及沙拉酱自身菌落总数、霉菌和酵母有良好的杀灭效果,1 kGy电子束辐照可降低致病菌3~6个log,菌落总数、霉菌和酵母不再检出。室温放置40 d后,感官评价发现1 kGy电子束辐照对沙拉酱色泽、体态、香气、滋味无显著影响,电子鼻分析、质构参数及离心解析率也与未辐照处理无明显差别,但2 kGy电子束辐照的滋味评分显著低于未辐照处理和1 kGy辐照处理,质构参数与未辐照处理、1 kGy辐照处理差异显著。电子束辐照可有效控制沙拉酱中致病菌,1 kGy剂量处理对沙拉酱色泽、质构、风味、稳定性无明显影响,可用于沙拉酱杀菌保鲜。     

电子束辐照技术及其在食品工业中的应用研究

电子束辐照技术作为一种冷杀菌技术,不存在放射性核泄露等安全性问题,可以作为γ辐射源的替代技术.文章结合近年来国内外文献报道,简述电子束辐照技术的原理、技术优势,及其在食品保鲜领域的研究应用现状,包括对肉类、果蔬、水产品的杀菌研究,以及电子束辐照技术对食品品质的影响研究等.     

高压二氧化碳处理对牛通脊颜色和肌红蛋白的影响

在35℃、30min,不同压力(0、7、14、21、28、35MPa)和在35℃、21MPa,不同时间(0、10、20、30、40、50min)对牛通脊进行高压二氧化碳(HPCD)处理,测定肉的色泽和肌红蛋白(Mb)指标的变化。结果表明:HPCD处理能使肉由红色逐渐变成灰棕色,显著提高L*值(p<0.05)、降低a*值(p<0.01)。在35℃、30min条件下,7、14、21MPa的处理分别使L*值提高4.891、9.494、16.432;a*值降低1.575、3.573、5.872。同时,HPCD处理显著降低了肌红蛋白的总量(p<0.01),7～35MPa处理后分别降低了0.034、0.048、0.054、0.044、0.061mmol/L/L。另外,提高压力、延长时间也能显著降低高铁肌红蛋白(MetMb)比例(p<0.05),提高氧合肌红蛋白(MbO2)比例(p<0.01)。4℃冷藏7d后,与对照组相比,HPCD处理均能提高肌红蛋白的稳定性。该研究为HPCD技术在肉类中的应用提供理论参考。     

冻藏对牛肉品质及氟喹诺酮类药物残留的影响

目的研究冻藏对牛肉品质和氟喹诺酮类药物残留的影响。方法将原料肉绞碎,分为空白组和加标组,真空包装,冻藏-18℃±1℃后进行主要营养成分、p H、TBARS、菌落总数、钙铁锌和氟喹诺酮类药物残留量的测定。结果在-18℃±1℃冻藏过程中,添加沙拉沙星(Sarafloxacin,SAR)和双氟沙星(Difloxacin,DIF)标品组和对照组牛肉水分含量随时间延长呈波动趋势,灰分含量逐渐上升,粗蛋白含量变化无规律;三项指标加标组和空白组差异显著(P0.05)。p H值随着贮藏时间的延长先下降后趋于平缓。加标组TBARS值在贮藏初期迅速下降,之后趋于平缓且低于空白组。铁、锌元素含量逐渐上升,钙含量在8~10周达到最大后开始下降。冻藏对牛肉中SAR和DIF含量的影响不显著。结论冻藏对本实验牛肉样品中氟喹诺酮类药物残留影响较小,实验牛肉样品符合卫生指标的贮藏时间是冻藏6周。     

Utilization of electron beam irradiated almond skin powder as a natural antioxidant in ground top round beef

ABSTRACT:  Defatted Carmel variety almond skin powder (ASP) irradiated at 0, 10, 20, and 30 kGy was mixed with ground top round beef at 0.5% (w/w) and stored at 4 °C. Color stability, peroxide values (PV), conjugated dienes (CD), thiobarbituric acid reactive species (TBARS), and hexanal were determined periodically over a 2-wk period. The L values were not affected by time or treatment. Initially, the redness ( a value) was higher for both the negative control with no ASP ( a value of 21.83) and positive control with 0.01% BHT ( a value of 22.33) compared to samples that contained the ASP ( a values from 17.70 to 20.17) on day 1. This decrease in redness was attributed to the presence of the ASP. Similar to day 1, the a values were not significantly different between the 2 controls over the duration of the study. All the samples with ASP exhibited lower lipid oxidation when compared to the negative control, with greatest oxidation retardation observed at 20 and 30 kGy. Over the treatment period, a 13% to 85% reduction in PV and a 40% to 80% reduction in TBARS were observed in the sample with 30 kGy ASP compared to the negative control. Generally, PV and TBARS of samples with ASP decreased with an increase in irradiation dose. While a difference due to irradiation dose was not observed in CD and hexanal content, the values were significantly lower ( P < 0.05) than the controls over time. This study demonstrates that almond skin power could be used to extend the shelf life of refrigerated ground raw beef.     

交变磁场对猪肉和牛肉冻藏品质的影响

以猪肉和牛肉为研究对象,探究交变磁场对其冻藏2,4,6,8周后品质的影响。结果表明：在1 mT交变磁场的作用下猪肉和牛肉样品相对于对照组降温速率更快,冰点分别降低了0.9,0.5 ℃,相变时间分别缩短了66.67%,65.00%;干耗损失和汁液损失明显减少、水分含量更高,且交变磁场组冻藏4周后样品的持水力仍大于80.00%;冻藏6周后对照组猪肉的挥发性盐基氮含量已超标达到了17.12 mg/100 g,而交变磁场组冻藏8周后才超过限量标准;另外pH值以及微生物数量也相对减少,并保持肉的色泽更鲜亮和感官品质更好。     

肉牛前肢与中部肌肉感官评定比较

利用评分检验法对肉牛前肢(冈上肌、冈下肌、臂三头肌)低档部位肉和中部(背最长肌、腰大肌)高档部位肉的嫩度、风味强度、多汁性进行感官评定比较。结果表明:腰大肌的风味强度、嫩度、多汁性得分都最高,冈下肌除风味强度得分低外,其他性质得分都与腰大肌相近。背最长肌的嫩度、多汁性得分都是最低。     

不同烹调方法对牛里脊营养和感官品质的影响

以牛里脊为研究对象,分别采用水煮、油煎和真空低温烹调三种烹调方法对牛里脊进行烹调,研究了不同烹调方法对牛里脊营养成分及感官品质的影响。结果表明,采用三种烹调方法烹制的牛里脊的菌落总数和大肠杆菌数均符合国家熟肉制品卫生要求,而采用真空低温烹调方法烹制的牛肉营养损失率和脂肪氧化程度最低,色泽和嫩度等感官品质最佳。综上所述,真空低温烹调方法作为一种新型的烹调方法,较传统烹饪方法而言,能更好地保留牛肉的营养成分和风味成分,具有较高的市场推广价值。      

Effects of gamma irradiation and electron beam irradiation on quality,sensory, and bacterial populations in beef sausage patties

This study compared effects of gamma ray (GR) and electron beam (EB) irradiation on quality (TBARS value, hardness, color), sensory characteristics, and total bacterial populations in beef sausage patties during accelerated storage at 30 °C for 10 days. Beef sausage patties were vacuum-packaged and irradiated by GR and EB at 0, 5, 10, 15, and 20 kGy at room temperature. The results of quality evaluation showed that the effects of GR irradiation were similar (p ? 0.05) to EB irradiation on lipid oxidation, hardness, color and sensory scores of the beef sausage patties. However, GR-irradiated samples had lower (p < 0.05) total bacterial counts than EB-irradiated samples after irradiation, and during storage regardless of irradiation dose. The results indicate that use of GR irradiation up to 10 kGy on patties should be useful in reducing bacterial populations with no adverse effect on quality and most of sensory characteristics (color, chewiness, and taste).     

Effect of gamma irradiation and frozen storage on chemical and sensory characteristics of rainbow trout (Oncorhynchus mykiss) fillet

The present study was conducted to evaluate the combined effect of low‐dose gamma irradiation (1, 3 and 5 kGy) and frozen storage (5 months at ?20 °C) on chemical and sensory characteristics of rainbow trout (Oncorhynchus mykiss) fillet. Our statistical analysis showed that irradiation process and frozen storage time had a significant effect (P < 0.05) on total volatile nitrogen (TVN), peroxide value (PV), thiobarbituric acid (TBA) and pH. The level of all of these factors increased with increasing frozen storage time. At the end of the fifth month of frozen storage, the lowest and the highest level of TVN, PV and TBA were corresponding to the irradiated samples at 3 and 5 kGy, respectively. In terms of the overall acceptability of their texture, odour, colour and taste, irradiated samples at 3 kGy had the best quality and remained acceptable after 5 months frozen storage. The optimum dose of gamma radiation of rainbow trout fillets according to chemical and sensory analysis was obtained at 3 kGy.     

Effect of irradiation and chilled storage on the microbiological and sensory quality of a ready meal

The sensory and microbiological quality of both non-irradiated and irradiated cook-chill ready meals consisting of roast beef and gravy, cauliflower and sauce together with roast and mashed potatoes were assessed at intervals during 15 d storage at 2–3°C.
Growth of Pseudomonas spp. caused obvious spoilage of the non-irradiated meals after storage, whereas spoilage was not apparent in the irradiated meals. Irradiation (2 and 3 kGy) reduced the number of microorganisms in the meal to <100 g⁻¹ initially and significant microbial growth did not occur during storage.
Using sensory profiling techniques a trained panel found that the effects of irradiation and chilled storage were most apparent in the cauliflower and potato components and occurred most often in the colour, appearance and textural attributes.
The combination of low dose irradiation and chilled storage effectively controlled microbial growth but changes in the sensory characteristics may limit the potential of irradiation to extend the shelf-life and enhance the safety of this ready meal.