辐照预处理促进玉米秸秆酶解糖化

以~(60)Co为辐照源,研究了0～2 000 kGy不同辐照剂量处理对玉米秸秆水解及酶解还原糖产量的影响,采用DNS法测定样品中水溶性还原糖的含量,探讨了辐照剂量与还原糖生成量的关系。结果表明,较高剂量的辐照对玉米秸秆有明显的降解糖化作用,经1200,1600,2000kGy剂量辐照后,玉米杆和玉米叶的还原糖含量分别提高了69.88%和445.63%;辐照后玉米秸秆易于酶解,随着辐照剂量的增大,酶解产糖量显著增加;在较高剂量下,辐照一酶解复合降解玉米秸秆效果优于单一的辐照处理和单一酶处理;辐照后的玉米秆和玉米叶经酶解处理,其还原糖含量分别增加了16.63%～184.13%和8.49%～228.45%,提高了纤维素原料的利用率。     

魔芋葡甘聚糖化学结构及生理功能研究进展

为了更好地开发利用魔芋葡甘聚糖(KGM),阐明了KGM独特的结构、优良的理化性质,综述了其生物活性的研究进展,分析了其结构与性能的关系,探讨了KGM的研究方向及其应用前景。     

机械力对魔芋葡甘聚糖影响研究

对机械力作用下魔芋葡甘聚糖的变化影响进行了研究总结,介绍了不同粉碎方式产生的机械力,以及机械力对魔芋葡甘聚糖的影响,并揭示机械力对魔芋葡甘聚糖影响的作用机理。对机械力作用其他多糖的研究提供理论指导,为KGM在机械力作用下的分子链保护提供理论指导,为魔芋葡甘聚糖乃至其他天然植物多糖的精深加工提供重要的依据。     

魔芋葡甘聚糖分子链空间结构的研究

魔芋葡甘聚糖(KGM)是提取自魔芋的天然大分子多糖,大量的KGM分子链能在凝固转变过程中形成高度有序的链结构,探讨链状结构稳定构象与功能性质的相关性,可以深入认识并揭示KGM纯化机制。综述了KGM微观构象与其链状空间结构的相关性,揭示KGM链状空间结构的微观机制。有助于深入认识KGM的复杂结构,为KGM链状空间结构的形成与调控提供理论指导,为KGM及其他天然植物多糖的深加工提供重要的依据。     

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。     

魔芋葡甘聚糖/蛋白酶提升鱼糜稳定性研究

以鱼糜制品为研究对象,通过测定鱼糜制品的凝胶强度、白度和持水率。系统地研究了蛋白酶(PT)的添加量、魔芋葡甘聚糖(KGM)的添加量、食盐添加量、淀粉的添加量等对鱼糜制品凝胶特性的影响,对鱼糜制品的精深加工、提高鱼糜制品质量方面提供依据。结果显示,最佳的工艺条件为食盐添加量3.0%,马铃薯淀粉添加量15.0%,PT添加量0.4%,KGM添加量0.5%。该配方下制作的鱼糜制品凝胶强度最佳。     

魔芋葡甘聚糖在板栗保鲜中的应用

2002年10月—2003年4月,在西北农林科技大学林学院进行了魔芋葡甘聚糖保鲜板栗试验,通过四种处理对比,结果为,0.3%的魔芋葡甘聚糖水溶液和0.3%的魔芋葡甘聚糖水溶液 0.2%的丙酸钙两个处理分别比对照降低呼吸强度53.7%、54.1%,减少水分损耗34.1%、41.3%,处理后的板栗在0~2℃条件下贮藏6个月后无霉坏发生,保鲜效果较好。     

魔芋葡甘聚糖在板栗保鲜中的应用研究

2002年10月—2003年4月,在西北农林科技大学林学院进行了魔芋葡甘聚糖保鲜板栗试验,通过四种处理对比,结果为,0.3%的魔芋葡甘聚糖水溶液和0.3%的魔芋葡甘聚糖水溶液＋0.2%的丙酸钙两个处理分别比对照降低呼吸强度53.7%、54.1%,减少水分损耗34.1%、41.3%,处理后的板栗在0~2℃条件下贮藏6个月后无霉坏发生,保鲜效果较好。     

电子束辐照对西瓜种子萌发的影响

以西瓜种子为材料,研究了电子束辐照对西瓜种子萌发的影响。结果表明,辐照电压200 KeV下,剂量超过30 kGy时降低了8424西瓜种子发芽势和发芽率,其中辐照剂量55 kGy和60 kGy的处理的发芽势与对照差异达到显著水平,辐照结合引发处理可以缓解辐照处理对种子负面效应;辐照电压100 KeV下,剂量为25 kGy的处理显著提高了美都、雷晓、黑津西瓜种子根长和芽长。说明合适的辐照电压和剂量可以促进西瓜种子萌发,不适合的辐照电压和剂量会延迟西瓜种子萌发,辐照后再进行引发处理可以缓解种子发芽延迟现象。     

红油金针菇辐照杀菌加工工艺研究

研究无防腐剂的红油金针菇产品辐照杀菌工艺,结果表明在红油金针菇调味过程中加入0.2%~0.3%的柠檬酸,既可使产品具有可口适中的酸味,又可起到一定的抑菌作用。当辐照剂量大于6 kGy时,可完全杀灭红油金针菇产品中的细菌,但红油金针菇产品的色泽开始下降,随着辐照剂量的增加,色泽下降明显。当辐照剂量大于8 kGy时,产品有辐照味产生,感官评分较低。结果表明,辐照杀菌剂量为4~6 kGy时,可使产品在安全达标的基础之上保证最佳口感。     

辐照处理对马铃薯粉降解作用的研究

为探明辐照对马铃薯粉的降解作用,采用不同剂量60Co-γ射线对其进行处理。结果表明,马铃薯粉经50~400 kGy剂量辐照处理后,颗粒形貌没有发生改变,但在冷水中的溶解度大大增加,其中经400 kGy剂量辐照处理后,溶解度达61%。辐照的直接糖化效率随处理剂量的加大而增加,其中以400 kGy剂量处理的最明显,糖化值（DE值）达5.1%。辐照处理的降解产物以麦芽糖和葡萄糖为主。试验证明60Co-γ射线能有效降解马铃薯粉,并可产生可发酵性糖。     

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.     

Effects of gamma and UV-C irradiation on the postharvest control of papaya anthracnose

Anthracnose is the main postharvest disease in papaya fruit. Today, there is considerable interest on alternative methods of control to promote resistance against pathogens and supplement or replace the use of fungicides. The goal of this work was to evaluate the effects of gamma and UV-C irradiation on Colletotrichum gloeosporioides, the causal agent of anthracnose. Mycelial growth, sporulation, and conidial germination were evaluated in vitro after fungal exposition to different irradiation doses. In the in vivo assays, ‘Golden’ papaya fruit were inoculated through subcuticular injections of a conidial suspension or mycelium discs. Next, fruit were submitted to different irradiation doses (0, 0.12, 0.25, 0.5, 0.75, and 1 kGy), using Co⁶⁰ as source, or UV-C (0, 0.2, 0.4, 0.84, 1.3, and 2.4 kJ m⁻²). To check the possibility of resistance induction by irradiation, papayas were also inoculated 24, 48, or 72 h after the treatments. The fruit were stored at 25 °C/80% RH for 7 days and evaluated for incidence and rot severity. The results showed that the 0.75 and 1 kGy doses inhibited conidial germination and mycelial growth in vitro. All doses increased fungal sporulation. The 0.75 and 1 kGy doses reduced anthracnose incidence and severity, but did not reduce them when the fruit were inoculated after irradiation. All UV-C doses inhibited conidial germination and those higher than 0.84 kJ m⁻² inhibited mycelial growth. The 0.4, 0.84, and 1.3 kJ m⁻² UV-C doses reduced fungal sporulation in vitro. There was no effect of UV-C doses and time intervals between treatment and inoculation on anthracnose control and fungal sporulation in fruit lesions. Moreover, all UV-C doses caused scald on the fruit. Thus, gamma irradiation can contribute for the reduction of postharvest losses caused by anthracnose and reduce the use or doses of fungicides on disease control.     

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.     

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。     

Effects of electron-beam irradiation on blueberries inoculated with Escherichia coli and their nutritional quality and shelf life

Fresh blueberries have become a popular new functional food because of their remarkably high levels of antioxidant phytonutrients and health benefits. However, the potential prevalence of human pathogens on blueberries has become an increased concern because they are consumed fresh. Procedures effective in decontamination and extending shelf life without affecting fruit quality are needed. Electron-beam irradiation was applied to fresh blueberries at the doses ranging from 0.5 to 3.0 kGy and its effectiveness for inactivating Escherichia coli (E. coli) K-12 and extending shelf life were investigated. The decimal reduction dose, D₁₀ values, of E. coli in cultural medium and blueberries were 0.43 ± 0.01 kGy and 0.37 ± 0.015 kGy, respectively. Irradiation reduced bacteria inoculated on blueberries from 7.7 × 10⁸ CFU/g to 6 CFU/g at 3.13 kGy and decreased the decaying of blueberries stored at 4 °C up to 72% and at room temperature up to 70% at this dose. No significant effect on the total monomeric anthocyanins, antioxidant activity, and l-ascorbic acid content of blueberries was observed from irradiation at doses ≤3 kGy. However, significant decreases in the antioxidant activity and l-ascorbic acid content were found in both control and irradiated blueberries after storage at 4 °C for 7 and 15 d. Information obtained in this study indicates that low dose electron-beam irradiation is effective in reducing E. coli and extending shelf life while maintaining the antioxidant properties of blueberries.     

高能电子束辐照处理对几种进口水果表皮色泽的影响

以泰国青芒果(honeys)、澳大利亚红芒果(R2E2)和台湾二林种杨桃为试材,研究电子束辐照处理对果实表皮色泽的影响,为电子束辐照检疫进口水果提供参考依据。结果表明,三种水果经0.43、0.85、1.26、1.68 kGy剂量的电子束辐照后立即观测,未发现肉眼可见的色泽变化,但总色差计算分析表明,辐照处理可导致果实产生色差,其中以0.43 kGy处理的色差最小,1.68 kGy处理的最大。货架条件(15~25℃)存放7 d后,不同辐照剂量处理的果皮色泽表现出明显的差异,果皮出现褐变,且剂量越大,褐变指数越高,其中泰国青芒果的后熟黄化受到抑制。因此,建议台湾二林种杨桃的适宜辐照剂量应在0.43 kGy以下,泰国青芒果和澳大利亚红芒果的适宜辐照剂量应在0.85 kGy以下。统计分析色泽参数(L*、a*、b*)与辐照剂量的相关性发现,三种水果果皮的红/绿轴参数a*与辐照剂量存在显著相关,在评价辐照果实色泽中具有重要意义。     

60Co-γ射线辐照处理对杉木种子萌发及幼苗生长的影响

为了探讨60Co-γ辐射剂量对杉木种子萌发及幼苗生长的影响,本研究以杉木第3 代种子园收集的种子为供试材料,研究了不同剂量的γ射线辐照处理对杉木种子发芽率、发芽时间、出苗率以及诱变苗早期生长的影响。结果表明：20 Gy辐照明显促进发芽,随着剂量的增加发芽率逐渐降低,80 Gy是致死剂量;辐照剂量20~60 Gy之间时,随着剂量的增加发芽时间会逐渐延长,出苗率会逐渐降低;γ射线辐照处理获得的诱变苗株高、地径和分枝数同样受剂量效应的影响,随着辐照剂量的增加,表现在植株矮化,地径变细,分枝数先升高后降低,尤其是40 Gy的辐照剂量能够显著促进分枝。根据辐照剂量与发芽率、出苗率可以初步确定,γ射线辐射杉木种子的半致死剂量在40~60 Gy之间。     

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。