γ射线辐照及保藏温度对米糕保质效果研究

为了研究辐照处理结合保藏温度对米糕保藏效果的影响,采用4,6,8,10 kGy剂量辐照米糕,在-18,4℃和常温环境中保藏,对其贮藏期内霉菌斑出现时间、气味感官评价、硬度及色度进行测定。结果表明,辐照处理对米糕中的霉菌生长起到了抑制作用,且10 kGy辐照处理完全杀灭了米糕样品中的霉菌;温度升高会加速米糕的老化程度,10 kGy辐照处理结合4℃环境可以改善米糕的老化程度,同时可以保持米糕特有的气味;10 kGy辐照处理对米糕色度影响最小。由此可知,米糕辐照综合保质的最优条件是10 kGy辐照处理结合4℃贮藏环境。     

电子束辐照处理对不同酱卤制品品质影响研究

以4种气调包装酱卤制品为研究对象,研究电子束辐照对酱卤制品品质的影响。将经电子束辐照的产品置于37℃下,检测其菌落总数,并对产品进行感官评价。结果表明,在37℃下放置78 d后,菌落总数均小于10 CFU/m L,贮藏早期(8 d)感官品质无明显影响。     

锡林浩特地区生鲜牛乳中微生物的调查与分析

通过对内蒙古锡林浩特市部分地区售卖的散装生鲜牛乳中的微生物进行检测,旨在分析季节及散卖生鲜牛乳对锡林浩特市生鲜牛乳质量的影响,以期为锡林浩特市散装生鲜乳销售环节的卫生质量安全监管及后期整顿提供基础数据。于2019年每个季节分别采集锡林浩特市不同片区4家散装售奶户生鲜牛乳,共16批次72份。通过国家标准方法,对散装生鲜牛乳中菌落总数、大肠菌群、金黄色葡萄球菌、沙门氏菌进行测定。72份样品菌落总数平均值为1.19×106CFU/m L,基本符合国家标准,1号散户夏季生鲜牛乳菌落总数达到2.38×106CFU/m L,已超过国家标准规定限值;大肠菌群平均值为4.98×104CFU/m L,4家生鲜牛乳中的大肠菌群最高值均出现在夏季;1份秋季样品检测出金黄色葡萄球菌,数值为24 CFU/m L;所有样品均未检测出沙门氏菌。结果表明,2019年内蒙古锡林浩特市散装生鲜牛乳售卖环节存在一定的微生物污染问题,季节对生鲜牛乳中的菌落总数和大肠菌群有一定影响,其中菌落总数影响较大。     

电子束辐照对储藏期间三文鱼鲜度的影响

为探究电子束辐照技术对三文鱼保鲜效果的影响,以新鲜三文鱼为原料,经不同低剂量（0~4 kGy）电子束辐照结合真空包装处理,研究4 ℃储藏条件下三文鱼的鲜度变化情况。以微生物菌落总数（Total bacterial counts, TBC）、挥发性盐基氮（Total volatile base nitrogen,TVB-N）含量及鲜度值（K值）为指标,并结合感官评价（Sensory assessment, SA）对三文鱼的鲜度进行综合评定,同时对各鲜度指标进行了相关性分析。结果表明,辐照剂量越高,杀菌效果越好;电子束处理后的三文鱼K值和TVB-N含量随贮藏时间的延长均呈现不同程度的增加,且冷藏期内其K值、TVB-N含量的上升速度均低于对照组;低剂量辐照对三文鱼感官品质影响不明显,其中经2、4 kGy辐照处理的三文鱼虽有一定的保鲜效果,但同时伴有色泽变淡,轻微辐照异味产生的现象。综合考虑,电子束辐照处理三文鱼的最佳辐照剂量为1 kGy,相应的货架期可达到12 d,与对照组相比,延长了6 d左右。同时三文鱼的K值与菌落总数、感官评分均具有极显著的相关性（P＜0.01）。     

香辛料中微生物在高能电子加速器下的D10值研究

D10值是指将微生物总数降低至其初始值10%所需要的辐照剂量。为确定香辛料采用电子加速器辐照的适宜灭菌剂量,以辣椒粉、大蒜粉、白胡椒粉三种常用的香辛料为原料,研究不同电子加速器的辐照剂量对其灭菌和D10值的影响。结果表明,辣椒粉、大蒜粉、白胡椒粉的菌落总数在高能电子加速器下的D10值分别是2.87、1.36和2.16,霉菌与酵母菌的D10值分别是2.90、1.59和2.77,香辛料中的大肠菌群与致病菌对电子束射线非常敏感,D10值较低,采用6 kGy以上的辐照剂量即可起到有效杀灭的作用。     

不同剂量电子束辐照对鲈鱼半成品灭菌及

为探讨电子束灭菌技术应用于鱼类加工半成品的最佳剂量,采用0~8.56 kGy辐照剂量对鲈鱼半成品进行灭菌,分析不同剂量电子束辐照对鲈鱼半成品菌落总数、pH、持水性、色度值、剪切力和挥发性成分的影响。结果表明,随辐照剂量的增加,杀菌效果增强;辐照剂量为3.70~4.41 kGy时菌落总数即可降至≤10 CFU·g-1;辐照剂量在2.45~7.24 kGy范围内能控制鲈鱼半成品pH的下降;辐照剂量高于8.56 kGy时,辐照对鱼肉持水力和剪切力无显著影响;辐照剂量低于6.64 kGy时,对鲈鱼半成品色泽的影响较小;与6.64 kGy相比,低剂量（3.33 kGy）辐照处理有利于减少烷类、烯类挥发性成分的产生。综上所述,电子束辐照剂量在4.00 kGy左右时,可达到灭菌目的,并有效控制鱼肉色度、pH和持水性,最大限度地保持产品原有风味和品质。     

预处理方法对鲜切菠萝微生物的影响

为保持和改善鲜切菠萝的贮藏品质,以‘巴厘’菠萝为试材,研究不同预处理方法（对照, 有机酸, 漂烫和有机酸+漂烫）对鲜切菠萝微生物的影响。结果表明：各处理的大肠菌群发生较少且总数极低;在对霉菌的影响上,漂烫处理的抑制效果最明显,至贮藏末期,其霉菌总数仅为CK的1/10,其次是综合处理;鲜切菠萝的酵母菌含量随着贮藏时间的延长不断增多,对照处理上升最快,其次是有机酸处理,而漂烫处理和综合处理的增加缓慢,至贮藏末期（11天）,分别比对照低1.7×106 cfu/g和1.5×106 cfu/g,处理间差异极显著（P<0.01）;鲜切菠萝的菌落总数不断增加,对照处理上升最快,其次是有机酸处理,漂烫处理的增加最慢。说明霉菌、酵母菌是鲜切菠萝的主要微生物,漂烫处理能够较显著地抑制鲜切菠萝霉菌、酵母菌和菌落总数的上升,防止果实腐烂变质,而对照和单独酸处理在鲜切菠萝品质保持方面的效果较差。     

不同清洗剂对鲜切生菜品质及贮藏期间微生物的影响

以鲜切散叶生菜为研究对象,分别研究在4℃贮藏条件下,自来水、次氯酸钠和氧泡泡颗粒3种清洗剂对其生理指标、感官品质和微生物生长情况的影响。结果表明,氧泡泡颗粒处理的鲜切生菜感官评分最高,在贮藏至第8天时,仍可以维持较好的品质,可溶性固形物含量比鲜样降低0.8%,维C含量降低1.09 mg/100 g,还原糖含量降低0.11%,叶绿素含量降低1.443 mg/100 g,在一定程度上延缓了生菜的萎蔫,从而延长其货架期,并且菌落总数小于6 lg(CFU/g),具有食用价值。氧泡泡鲜氧颗粒可用于鲜切散叶生菜的清洗,在抑制微生物生长繁殖的同时可以维持较好的感官品质。     

等离子体活化水对大肠杆菌及染菌鲜切青椒品质的影响

以鲜切青椒为原料,通过测定染菌青椒贮藏过程中的菌落总数、感官评分、失重率、硬度、色度和VC含量等指标,探究等离子体活化水(Plasma-activated water,PAW)对鲜切青椒微生物的抑制作用及对其品质的影响.结果表明:随着制备时间的增加,PAW的抑菌效果逐渐增强,其中PAW60对大肠杆菌的抑菌率可达95.52％.贮藏期间,随着PAW60喷雾时间的延长,染菌青椒的感官评分先上升后下降,硬度上升,亮度下降,黄度上升,VC含量总体呈先上升后下降的趋势.与未喷雾组相比,PAW60喷雾60 min时,染菌青椒菌落总数可显著下降至0.23×102 CFU/mL,青椒的亮度和绿度显著提高,黄度显著下降(P＜0.05).贮藏4 d时,PAW60喷雾60 min组青椒的VC含量为(59.96±4.92)g/100 g,高于或显著高于其他染菌组(P＜0.05).综上,PAW制备时间和对青椒的喷雾时间均控制在60 min左右时,有利于鲜切青椒的抑菌及其品质的保持.     

冰鲜鸡肉贮藏过程中品质变化研究

无菌采集冰鲜鸡肉,置于4℃下贮藏,并进行菌落总数、挥发性盐基氮、pH值和感官指标的测定。结果表明,冰鲜鸡胸肉样品在96 h时各项指标接近标准值,分别为菌落总数5.61±0.22 log CFU/g,挥发性盐基氮14.78±0.12 mg/100 g,pH值6.61±0.4,感官指标一般。当贮藏期为144 h时,各项指标超出国家相关标准,达到腐败变质的程度。     

Efficacy of gamma irradiation for protection against postharvest insect damage and microbial contamination of adlay

This study examines the protective effects of gamma irradiation against postharvest insect damage and microbial contamination and its effect on the nutritive value of adlay (Coix lacryma-jobi L.). Adlay was treated with doses of 0–20 kGy gamma irradiation and subsequently stored at ambient temperature. The number of insects, microbial quality and chemical properties of irradiated and non-irradiated adlay were evaluated immediately after treatment and after 6 months of storage. Before irradiation, total aerobic microbial counts ranged from 5.6 × 10² to 1.4 × 10⁵ CFU g⁻¹ and the mean total number of insects was 3.2 ± 2.1 per 100 g of polished kernel. Two kilograys was the lowest dose that provided 100% insect control. A radiation-resistant bacterium, Deinococcus radiodurans RC1, was found in 2 of 10 adlay samples. Four kilograys was a sufficient dose for Enterobacteriaceae inactivation, and 6 kGy was a sufficient dose for yeast and fungi inactivation. Twenty and 8 kGy sufficed for the inactivation of all mesophilic microbes in samples with and without D. radiodurans, separately. Moreover the moisture, ash, crude fiber, crude fat, crude protein and riboflavin content all remained constant. However, 8 kGy irradiation reduced vitamin B1 concentration by 24.2%, but did not measurably reduce the amount of amino acids, except methionine and cysteine. Fatty acid contents did not alter after 8 kGy irradiation, but changes were observed after the 6 months of storage. These changes caused by irradiation were no greater than those caused by the 6-month storage. Irradiation up to 8 kGy did not markedly increase the acid value, but did increase the peroxide value to 13% of the initial value right after irradiation. However, significant changes in acid value and peroxide value were noted after 6 months of storage both in non-irradiated and post-irradiated storage samples. Additionally, 8 kGy irradiation did not significantly change the adlay appearance. The improvement in the hygiene of this vital food source compensates for the small loss of some nutritional constituents. Hence 8 kGy of gamma irradiation can be used in cold decontamination of adlay to prolong shelf-life, to improve postharvest quality, and to reduce the risk of food-borne disease.     

60Co-γ射线辐照处理对毛竹防霉性能和尺寸稳定性的影响

摘要：通过不同剂量{0kGy（CK）、0.2kGy、0.3kGy、0.5kGy、1kGy、3kGy、5kGy、10kGy、100kGy、200kGy}辐照处理毛竹,研究其对毛竹防霉性能的影响。结果表明：（1）毛竹经3kGy辐照后刷桐油处理的防霉效果较好,防治效力达到60.16%;（2）辐照处理毛竹的密度,干缩率等与对照相比无显著影响。     

Efficacy of gamma irradiation for protection against postharvest insect damage and microbial contamination of adlay

This study examines the protective effects of gamma irradiation against postharvest insect damage and microbial contamination and its effect on the nutritive value of adlay (Coix lacryma-jobi L.). Adlay was treated with doses of 0–20 kGy gamma irradiation and subsequently stored at ambient temperature. The number of insects, microbial quality and chemical properties of irradiated and non-irradiated adlay were evaluated immediately after treatment and after 6 months of storage. Before irradiation, total aerobic microbial counts ranged from 5.6 × 10² to 1.4 × 10⁵ CFU g⁻¹ and the mean total number of insects was 3.2 ± 2.1 per 100 g of polished kernel. Two kilograys was the lowest dose that provided 100% insect control. A radiation-resistant bacterium, Deinococcus radiodurans RC1, was found in 2 of 10 adlay samples. Four kilograys was a sufficient dose for Enterobacteriaceae inactivation, and 6 kGy was a sufficient dose for yeast and fungi inactivation. Twenty and 8 kGy sufficed for the inactivation of all mesophilic microbes in samples with and without D. radiodurans, separately. Moreover the moisture, ash, crude fiber, crude fat, crude protein and riboflavin content all remained constant. However, 8 kGy irradiation reduced vitamin B1 concentration by 24.2%, but did not measurably reduce the amount of amino acids, except methionine and cysteine. Fatty acid contents did not alter after 8 kGy irradiation, but changes were observed after the 6 months of storage. These changes caused by irradiation were no greater than those caused by the 6-month storage. Irradiation up to 8 kGy did not markedly increase the acid value, but did increase the peroxide value to 13% of the initial value right after irradiation. However, significant changes in acid value and peroxide value were noted after 6 months of storage both in non-irradiated and post-irradiated storage samples. Additionally, 8 kGy irradiation did not significantly change the adlay appearance. The improvement in the hygiene of this vital food source compensates for the small loss of some nutritional constituents. Hence 8 kGy of gamma irradiation can be used in cold decontamination of adlay to prolong shelf-life, to improve postharvest quality, and to reduce the risk of food-borne disease.     

Irradiation of ‘Boufeggous’ dates: Effects on chemical composition during storage

Moroccan dates Phoenix dactylifera L. cv. Boufeggous were treated with 0.6, 0.9 and 1.8 kGy of gamma irradiation and subsequently stored at ambient temperatures. Chemical properties were evaluated for irradiated and non-irradiated dates immediately after the treatment, 4 and 8 months of storage. No significant changes were noted in dry matter, total lipid and protein contents. Irradiation at higher doses (0.9 and 1.8 kGy) increased titratable acidity immediately after the treatment. After 8 months of storage, the treatment increased ash and decreased amino acids. Irradiation at 0.9 kGy significantly increased glucose and total sugars contents after 8 months of storage. Fructose amounts were, however, not affected by the treatment. The increase in storage time resulted in a decrease in starch contents in both irradiated and non-irradiated dates. Pectic substances (water-, oxalate- and hydrochloride-soluble fractions) were significantly reduced by the treatment with a 27% decrease in water-soluble pectins at a dose of 1.8 kGy at the end of the storage time.     

高能电子束辐照对鲜切牛蒡贮藏品质和褐变的影响

分别采用0.5、1.0 kGy剂量的电子束处理牛蒡鲜切片,测定分析其在(3±1)℃温度下贮藏8 d期间生理和品质的变化,研究不同剂量高能电子束辐照对鲜切牛蒡贮藏品质和褐变的影响。结果表明:高能电子束辐照处理能明显延缓鲜切牛蒡贮藏过程中的褐变;抑制多酚氧化酶(PPO)、苯丙氨酸解氨酶(PAL)、4-香豆酸辅酶A连接酶(4CL)的活性;降低总酚物质和丙二醛(MDA)含量,有助于维持鲜切牛蒡的贮藏品质。其中以1.0 kGy剂量辐照处理的鲜切牛蒡防褐变保鲜效果为好。     

天麻核桃糕的研制

为了进一步开发利用天麻和核桃,以新鲜天麻和核桃为主要原料,通过糖制工艺制备天麻核桃糕。以感官评分为评价指标,通过单因素试验和响应面法优化天麻核桃糕的制作工艺,并对产品进行质构及微生物指标的测定。结果表明,天麻核桃糕的最佳制作工艺为：麦芽糖醇添加量55 g,核桃仁添加量30 g,天麻添加量50 g,红枣添加量35 g,冰糖添加量15 g,蜂蜜添加量15 g,天麻炒制时间4 min,糖液熬制时间7 min。对此条件下制得的产品进行质构分析,结果显示,硬度为26.41 kg,粘合度为175.192 g·s,凝聚力为0.363,黏性为9 231,咀嚼性为4 635 mJ,弹性为0.194 Pa;微生物指标检测结果为：菌落总数60 CFU/g,大肠菌群10 CFU/g,致病菌未检出。以此法制备的天麻核桃糕呈均匀有光泽的焦糖色,具有天麻、核桃和红枣复合滋气味,口感细腻,咀嚼性及弹性良好,结构完整,方便食用。研究结果为天麻产业的发展提供了技术支持。     

咸肉的加工工艺与辐照保质研究

咸肉风味独特,深受消费者欢迎。咸肉加工工艺的关键,是在上盐工序中把握加盐量和操作时间,堆放肉要平叠压好,腌渍温度控制在8~12℃;4 kGy辐照冷藏处理的咸肉,在保藏90 d后的菌落总数小于1×102 cfu/g,脂肪色泽白皙,过氧化值为20.5 meq/kg,感官指标最好。     

青麦仁冻藏期内菌相分析及优势菌的分离鉴定

为了对青麦仁冻藏期间微生物进行控制,本研究利用选择性培养基对冻藏期间青麦仁的菌相进行分析,应用形态学观察、生理生化鉴定和16S rDNA序列分析法鉴定速冻青麦仁的优势菌株,探讨青麦仁冻藏期内菌相构成及优势微生物种类。结果表明,青麦仁冻藏期内细菌总数为3.76 lg(CFU/g),经分离纯化后得到特异性细菌菌株28株、真菌3株,菌落基本形态观察及菌落总数计数得到速冻青麦仁中优势菌群3株,经生理生化鉴定及16S rDNA序列测定可知速冻青麦仁中的3株优势菌分别为:QX-1鞘氨醇单胞菌属、QX-4微杆菌属和QX-26不动杆菌属。