高能电子束辐照对草莓常温贮藏品质的影响

为提高草莓采后品质和延长保鲜时间,促进电子加速器在鲜活农产品保鲜方面的研究和应用,文中研究了0.5、2.0、3.5和5.0kGy不同剂量电子束辐照处理对丰香草莓常温贮藏性状的影响及微生物控制效果。结果显示:电子束辐照后常温(18-20℃)贮藏期间,2.0-3.5kGy辐照处理能够有效控制微生物的生长,使草莓保鲜期延长了2-6d(腐烂指数<0.3),且3.5kGy辐照对果实硬度、水分、糖、酸及Vc等贮藏品质的保持效果较好。5.0kGy辐照虽然能够有效抑制微生物的生长,但是对草莓营养品质有一定负面影响,可作为电子束辐照草莓的最高极限剂量。     

电子束辐照的熟制鲢鱼块贮藏品质分析

该研究以熟制鲢鱼块为原料,使用0、4、8 kGy电子束辐照处理后,分别置于常温和4 ℃中贮藏,通过测定贮藏期间样品菌落总数（TVC）、pH值、硫代巴比妥酸值（TBA）、过氧化值（POV）、挥发性盐基氮值（TVB-N）与质构的变化,研究不同辐照剂量及贮藏温度对熟制鲢鱼块贮藏品质的影响。结果表明,辐照剂量越高对熟制鲢鱼块杀菌效果越好,4 ℃贮藏杀菌效果优于常温贮藏。贮藏温度对鲢鱼块pH值无明显影响,但8 kGy辐照处理会降低鱼块pH值（P<0.05）。鲢鱼块TBA值随着辐照剂量的增加而增加,但不同辐照剂量、不同贮藏温度之间无显著差异（P>0.05）。与未辐照组相比,电子束辐照能有效抑制鱼块POV值和TVB-N值的升高（P<0.05）。质构测定结果显示,当贮藏温度为4 ℃、辐照剂量为4 kGy时,可保持杀菌效果的同时改善熟制鲢鱼块的硬度、弹性和咀嚼性等指标。综合考虑,以4 kGy辐照剂量处理熟制鲢鱼块,并选择贮藏温度4 ℃,其保鲜效果最佳。以上研究可为鲢鱼电子束辐照贮藏保鲜技术的推广应用提供理论依据。     

低剂量电子束辐照对徐香猕猴桃生理品质与氧化酶的影响

为明确低剂量电子束辐照对徐香猕猴桃采后生理品质以及相关氧化酶的影响。以徐香猕猴桃为试验材料,经0（对照）、200和400 Gy低剂量电子束进行辐照后,于温度0～1℃、相对湿度90%～95%冷库中贮藏,定期测定硬度、失重率、可溶性固形物含量、可滴定酸、呼吸速率、总叶绿素、维生素C、丙二醛、氧化酶活性指标,研究低剂量电子束对猕猴桃采后贮藏品质的影响。结果表明,低剂量电子束辐照处理可以显著抑制猕猴桃硬度、失重率、可滴定酸及维生素C含量的下降,延缓可溶性固形物含量上升,降低呼吸速率,在贮藏后期有效抑制了叶绿素的分解,减少丙二醛含量的积累。在贮藏期126 d时,200和400 Gy处理组的硬度分别比对照组高58.96%和82.45%,失重率分别比对照组低12.4%和27.27%。同时,不同辐照处理组均能保持较低的多酚氧化酶活性水平,且400 Gy辐照处理组过氧化物酶与过氧化氢酶活性最高峰峰值比对照组高43.63%和21.36%。综合认为,低剂量电子束辐照可以通过影响猕猴桃采后贮藏生理品质和氧化酶活性来延缓果实衰老,从而达到猕猴桃保鲜的目的,且400 Gy剂量电子束辐照组效果最好。该研究为低剂量电...     

电子束辐照后即食小龙虾贮藏品质的变化

该研究探讨了4 kGy电子束辐照（EBI4）与8 kGy电子束辐照（EBI8）处理对于即食小龙虾尾在冷藏条件下贮藏期内品质的影响。测定了贮藏期内菌落总数、TVB-N、TBA、pH、感官品质的变化,以及贮藏前后电子鼻的变化。结果表明,4 kGy与8 kGy电子束辐照处理后,都有效抑制了微生物的生长繁殖,在贮藏期结束时,微生物仍未超过限定值,分别为4.64 lg CFU/g和4.26 lg CFU/g。且在贮藏期内TVB-N值得到有效抑制,能较好的保持虾肉不致腐败。与8 kGy相比,4 kGy辐照处理能更好保持即食小龙虾的品质,脂肪氧化程度更低,pH值变化与未经辐照的小龙虾更为相近,且在贮藏期内感官评价可接受度更高。经过4 kGy电子束辐照后与新鲜即食小龙虾气味更为相近,对于风味的保留更好。因此,在实际生产中,选取4 kGy电子束辐照处理结合冷藏更有利保持即食小龙虾尾的品质。     

电子束辐照对手撕牛肉贮藏品质的影响

以真空包装的手撕牛肉为材料,辐照剂量分别为2、5、8、10、15、20 kGy,研究高能电子束辐照对手撕牛肉品质的影响。探究在不同辐照剂量下,手撕牛肉在25℃下贮藏63 d过程中的品质变化。结果表明,辐照处理组的手撕牛肉在贮藏期内的菌落总数较对照组明显减少;当辐照剂量大于8 kGy时,能明显延长手撕牛肉的贮藏期;电子束辐照对手撕牛肉的剪切力、咀嚼性和pH值并未产生明显影响;对硫代巴比妥酸（thiobarbituric acid,TBA）值的影响较小;随着辐照剂量的增加,感官评分出现一定程度的下降,当辐照剂量大于10 kGy时,辐照组的色泽评分明显低于对照组。综合分析各项指标可得：8 kGy～10 kGy的辐照剂量既能最大限度保留手撕牛肉的原本品质,又能保障其安全性。     

电子束辐照对不同品种猕猴桃品质的影响

以4 个品种（‘海沃德’‘徐香’‘华优’‘亚特’）猕猴桃为试材,采用剂量分别为0.4、0.8、1.2 kGy的高能电子束辐照处理,于0～1 ℃、相对湿度90%～95%条件下贮藏,每15 d取样一次,测定电子束辐照处理对果实冷藏期硬度、质量损失率、可溶性固形物质量分数、可滴定酸质量分数、VC含量等品质指标的影响,探究电子束辐照对猕猴桃贮藏品质的影响,为猕猴桃采后保鲜技术提供理论依据。结果表明,电子束辐照处理对维持猕猴桃的贮藏品质有一定积极作用。适宜剂量电子束辐照能抑制猕猴桃贮藏期间果实的质量损失,延缓可滴定酸质量分数的下降,提高类黄酮含量,在贮藏前期提升多酚含量,但硬度、VC含量经辐照后有所降低,且可溶性固形物质量分数升高。相比其他剂量,0.8 kGy电子束辐照能够较好地延缓猕猴桃可溶性固形物质量分数升高和可滴定酸含量降低,提高多酚和类黄酮的含量。整体来看,4 个品种中‘海沃德’‘亚特’更加耐受电子束辐照,且0.4、0.8 kGy剂量的电子束辐照对‘海沃德’‘亚特’的采后贮藏保鲜效果较好,推荐0.4、0.8 kGy为‘海沃德’‘亚特’的采后保鲜辐照剂量。结论：适宜剂量的电子束辐照可以作为提升猕猴桃保鲜效果的有效手段。     

电子束辐照对芒果品质的影响

为研究电子束辐照处理对芒果品质的影响,筛选适用于芒果辐照保鲜的最佳剂量,分别采用0.5、1.0、1.5和2.0 kGy剂量电子束辐照芒果,测定室温贮存条件下辐照处理后芒果发病率、失重率以及营养指标的变化情况。结果表明：不同剂量的电子束辐照处理对芒果的硬度、可溶性固形物、抗坏血酸、总酸和还原糖等营养成分含量没有显著性影响;但0.5和1.0 kGy辐照处理能使芒果保持良好的外观品质,延缓其褐变速度,降低其腐烂率和失重率,抑制果实后熟转黄,保持水果的色泽;而1.5和2.0 kGy剂量辐照处理一定程度上加速了芒果的褐变和腐烂,降低其外观品质和色泽,尤其是2.0 kGy辐照处理组,其腐烂变质速度最快。对芒果来说,其电子束辐照保鲜处理的最佳辐照剂量为0.5~1.0 kGy。     

电子束辐照对核桃糕品质的影响

以土特产食品店自制自售的散装核桃糕为试材,研究了电子束辐照对核桃糕品质的影响,分析了在1、2、3、4和5 kGy剂量辐照处理条件下核桃糕的酸价、过氧化值、大肠菌群、菌落总数、霉菌和感官品质的变化情况.结果表明:随着辐照剂量的增加,微生物的存活率减少,感官得分减少,酸价、过氧化值增加;核桃糕经2 kGy剂量辐照,可杀死1...     

气调包装结合电子束辐照对蚌肉冰藏品质的影响

为进一步分析气调包装结合电子束辐照对冰藏蚌肉品质的影响,该研究设置对照组（CK）、气调包装组（Modified Atmosphere Packaging,MAP）、电子束辐照组（Electron Beam Irradiation,EB）以及气调包装结合电子束辐照组（Modified Atmosphere Packaging Combined with Electron Beam Irradiation,MAP+EB）,通过测定冰藏初始点和货架期终点时蚌肉的质构、色泽、挥发性风味物质和脂肪酸组成指标综合评价蚌肉的品质。结果表明,电子束辐照后蚌肉的硬度、咀嚼性降低,但可延缓微生物繁殖对蚌肉质构的影响。蚌肉色差值在冰藏初始点各组间无显著差异（P>0.05）,在货架期终点,受电子束辐照影响,EB组和MAP+EB组的L*值下降,b*值上升。冰藏初始点,CK、MAP、EB和MAP+EB组蚌肉中挥发性风味物质的种类分别为8、17、16和19种,说明气调包装和电子束辐照处理显著提高挥发性风味物质的种类（P<0.05）,并且醛类、酮类物质总含量提高,烃类、醇类物质总含量降低,但无显著差异（P>0.05）。各保鲜组蚌肉中脂肪酸相对总含量分别为49.55%、49.64%、49.61%和49.90%,无显著差异（P>0.05）。综上,气调包装结合电子束辐照对冰藏蚌肉的贮藏品质无明显的不良影响,适合于蚌肉的物理保鲜。     

电子束辐照对鸡肉营养品质的影响

采用高能电子束对冷冻鸡肉进行辐照,考察了辐照前后鸡肉中蛋白质、维生素、脂肪等营养成分的变化。结果表明,在2～10kGy辐照剂量范围内,鸡肉中蛋白质、脂肪以及感官品质未发生明显变化,而几种维生素均有不同程度的损失。     

电子束辐照对稻米储藏特性及品质的影响

为考察稻谷、糙米、精米经电子束辐照处理后的保鲜效果及品质变化,选取新收获的晚粳稻为原料,研究0,2,4kGy剂量辐照对稻谷、糙米、精米的保鲜效果,并考察电子束辐照对稻米理化性质,包括水分含量、色泽、脂肪酸值、黏度值和食味值的影响。结果表明,经2,4kGy剂量辐照的稻谷、糙米、精米与未辐照的样品相比,水分含量、色泽无显著变化(P0.05),黏度值显著下降(P0.05),且储藏一段时间后,经电子束辐照过的样品较未辐照的样品脂肪酸值上升更缓慢,食味值变化更小,即储藏期间品质劣变程度更小。电子束辐照技术作为一种冷杀菌技术,可用于保持稻米的品质和营养、延长稻米储藏期。     

辐照技术在粮食储藏中的应用

电子束辐照灭茵杀虫技术是近年在国内外发展、应用很快的新兴技术。重点介绍了电子加速器辐照技术在粮食储藏方面的研究进程和应用技术。采用该技术完成除虫作业,具有高效、安全、环保、经济等优点。     

Effect of electron beam irradiation on quality indicators of peanut butter over a storage period

Electron beam (e-beam) irradiation is an effective non-thermal processing step for the reduction of Salmonella in peanut butter. The objective of this study was to evaluate the effects of e-beam irradiation on quality indicators of peanut butter. Peanut butter samples were exposed to a range of e-beam doses and examined over a 14-day period at 22 °C. Colour analysis (L^∗, a^∗, b^∗), spreadability, peroxide values (PV) and thiobarbituric acid reactive substances test (TBARS) for lipid oxidation were monitored, fatty acid and amino acid profiles were verified and protein degradation was determined by sodium dodecyl sulphate–polyacrylamide gel electrophoresis (SDS–PAGE). Changes in colour, PV, and TBARS were observed as e-beam dose increased. No significant changes in spreadability were observed (P > 0.05). When applied to peanut butter, e-beam irradiation will produce significant changes in quality indicators; future studies should include sensory evaluation and consumer acceptance studies.     

电子束辐照对涤纶染色性能的影响

使用不同剂量电子束对涤纶织物进行辐照处理,研究了涤纶织物处理前后结晶度和表面形态的变化,对辐照前后涤纶织物染色,分析辐照对染色性能的影响和色牢度的变化情况。研究表明,100kGy的辐照会造成涤纶结晶度上升,染色速率下降,但最终的染色K/S值增加;200kGy辐照会造成涤纶结晶度下降,染色速率上升,但最终K/S下降;400kGy辐照会造成涤纶表面粗糙化,染色K/S上升。     

Effects of electron beam irradiation on microbial inactivation and quality of kimchi paste during storage

The effects of electron beam irradiation on microbial inactivation and quality of noninoculated and inoculated (Listeria monocytogenes) kimchi pastes were examined. Kimchi paste samples were irradiated at doses of 2, 4, 6, 8 and 10 kGy and stored for 21 days at 4 °C. Irradiation (10 kGy) reduced the populations of total aerobic bacteria, lactic acid bacteria, and yeast and moulds in the samples by 1.72, 2.24 and 0.86 log CFU g^?1, respectively, compared to the control. In particular, coliforms were not detected at 8 and 10 kGy, and the population of L. monocytogenes in inoculated samples was significantly decreased by 2.67 log CFU g^?1. Electron beam irradiation delayed the changes in O₂ and CO₂ concentrations, pH, acidity and reducing sugar content observed in kimchi paste during storage. These results suggest that electron beam irradiation can be used to improve the microbiological safety and shelf life of kimchi paste.     

Effect of electron beam irradiation on the shelf life of mozzarella cheese

The effectiveness of electron beam irradiation on the shelf life of mozzarella cheese was evaluated using five different irradiation doses and a control cheese. Shelf life tests were run at 10 °C by determining the cell load of spoilage micro‐organisms monitored on the consecutive days during storage. By fitting the experimental data through a modified version of the Gompertz equation, the shelf life of samples irradiated to the different doses was calculated. Results show significant increases in the shelf life of the investigated cheese. There were slight differences in the functional properties such as stretching, oiling off, melting between irradiated and unirradiated cheeses at 260 °C in oven. Our results indicated that the electron irradiation at the dose of 2.0 kGy may inhibit the growth of spoilage micro‐organisms such as coliforms and Pseudomonas sp. without affecting the sensorial characteristics of the product.     

高能电子束辐照剂量方式对白酒挥发性成分的影响

采用顶空固相微萃取（HS-SPME）/气-质联用（GC-MS）技术,对高能电子束不同辐照剂量方式处理浓香型白酒的挥发性成分进行了测定与分析。结果表明,经过单圈8 kGy剂量的辐照处理,白酒挥发性成分由76种增至83种,其中酯类增加4种,相对含量由82.2%降至81.13%,酸类种类不变,相对含量由4.03%增至4.21%,这与其他浓香型白酒熟化过程中变化趋势一致,对其具有催陈效果。保持白酒总的辐照剂量不变,分别降低单圈辐照剂量至4 kGy、2 kGy、1 kGy,白酒的挥发性成分由83种分别降至82、74、52种,相对含量由95.54%分别降至83.89%、75.58%和68.16%,除烃类物质增加外,酯类、酸类、醇类、醛类物质相对含量均显著降低。采用单圈辐照剂量处理的方式有助于浓香型白酒熟化,提升了品质。     

Effect of food characteristics, storage conditions, and electron beam irradiation on active agent release from polyamide-coated LDPE films

ABSTRACT:  We investigated the effect of electron beam irradiation, storage conditions, and model food pH on the release characteristics of trans -cinnamaldehyde incorporated into polyamide-coated low-density polyethylene (LDPE) films. Active agent release rate on irradiated films (up to 20.0 kGy) decreased by 69% compared with the nonirradiated controls, from 0.252 to 0.086 μg/mL/h. Storage temperature (4, 21, and 35 °C) and pH (4, 7, and 10) of the food simulant solutions (10% aqueous ethanol) affected the release rate of trans -cinnamaldehyde. As expected, antimicrobial release rate decreased to 0.013 μg/mL/h at the refrigerated temperature (4 °C) compared to the higher temperatures (0.029 and 0.035 μg/mL/h at 21 and 35 °C). The fastest release rate occurred when exposed to the acidic food simulant solution (pH 4). In aqueous solution, trans -cinnamaldehyde was highly unstable to ionizing radiation, with loss in concentration from 24.50 to 1.36 μg/mL after exposure to 2.0 kGy. Fourier transform infrared (FTIR) analysis revealed that exposure to ionizing radiation up to 10.0 kGy did not affect the structural conformation of LDPE/polyamide films and the trans -cinnamaldehyde in the films, though it induced changes in the functional group of trans -cinnamaldehyde when dose increased up to 20.0 kGy. Studies with a radiation-stable compound (naphthalene) showed that ionizing radiation induced the crosslinking in polymer networks of LDPE/polyamide film and caused slow and gradual release of the compound. This study demonstrated that irradiation serves as a controlling factor for release of active compounds, with potential applications in the development of antimicrobial packaging systems.     

Effect of electron beam irradiation on color and microbial bioburden of red paprika

The effect of irradiation with electron beams on the microbiological quality and color properties of red paprika was examined. The irradiation doses ranged from 0 to 12.5 kGy. The counts performed were total mesophilic aerobic microorganisms, Enterobacteriaceae, coliforms, sulfite-reducing clostridia, molds, and yeasts. It was concluded that molds, yeasts, and sulfite-reducing clostridia were the most resistant species, although a 10-kGy dose of irradiation leads to optimum sanitation. Extractable color and apparent color were analyzed to appraise the incidence of the irradiation treatments in the color properties of red paprika. Extractable color was determined according to the American Spice Trade Association method, and apparent color was analyzed by reflectance using the CIELab color space. Data showed no significant differences between the color properties of irradiated and nonirradiated samples. Irradiation was a suitable procedure to minimize the bioburden of red paprika with small modifications of its color properties.