壳聚糖可食用膜对油豆角贮藏生理的影响

使用壳聚糖配制的涂膜液处理油豆角,通过测定涂膜的油豆角在贮藏期间呼吸强度、PPO、POD、MDA的变化,探讨油豆角在贮藏期间的生理变化规律.结果表明,涂膜处理后能推迟油豆角呼吸高峰的到来;同时,在贮藏期间,涂膜油豆角的呼吸强度、PPO、POD、MDA与对照组相比都有所降低.     

涂膜与臭氧杀菌在油豆角保鲜中的应用研究

采用涂膜与臭氧杀菌相结合的方式对油豆角进行保鲜。结果表明:与传统的涂膜法相比,该方法能有效降低油豆角在贮藏过程中的减重率、褐斑率和腐烂率。将油豆角置于8～10℃、相对湿度90%～95%的环境中贮存到30d,经涂膜处理的油豆角感官指标5级,降低了商品价值;经涂膜与臭氧杀菌综合处理的油豆角感官指标3级、外观良好,具有较高的商品价值。     

壳聚糖及其衍生物对油豆角保鲜效果的研究

分别用壳聚糖和羧甲基壳聚糖配制的涂膜液处理油豆角,比较不同处理组的生理指标及感官指标,确定保鲜效果较好的涂膜液。结果表明,涂膜处理的油豆角呼吸强度、多酚氧化酶和过氧化物酶活性及丙二醛含量与对照组相比都有所降低;用N,O羧甲基壳聚糖处理的油豆角保鲜效果较好。     

油豆角冰温贮藏对淀粉与蛋白质降解速度的影响

以"将军"油豆角为试材,分析了不同温度贮藏过程中油豆角淀粉、可溶性糖、可溶性蛋白和游高氨基酸的变化。结果表明:0℃冰温贮藏的油豆角淀粉和可溶性蛋白降解的速度最慢,8℃次之,25℃最快;不同温度贮藏期间可溶性糖含量有差异,25℃贮藏油豆角的果糖、葡萄糖、蔗糖和总糖含量迅速降低,8℃贮藏油豆角可溶性糖消耗速度大于冰温贮藏,其果糖、葡萄糖、蔗糖和总糖含量低于冰温贮藏的油豆角;冰温贮藏末期油豆角游离氨基酸总量及必需氨基酸含量均高于8℃。     

影响气调贮藏油豆角因素的研究

在气调贮藏(O22%～3%,CO22%～3%)油豆角实验过程中,研究了贮藏环境温度、成熟度及品种对贮藏效果的影响。结果表明:10℃左右是贮藏油豆角较适宜温度,成熟度适中的油豆角贮藏效果较佳;不同品种的油豆角贮藏效果差异较大,紫花油豆角耐贮性相对较好。     

可食性膜对油豆角贮藏期间品质的影响

采用正交实验设计配制保鲜剂 ,测定经处理的油豆角在贮藏期间水分及营养成分的变化 ,探讨油豆角贮藏期间品质的变化规律 ,结果表明 :随着贮藏时间的延长 ,油豆角中水分、Vc和还原糖的含量不断下降 ;叶绿素的含量初期下降 ,随后升高并出现累积峰 ,最后又趋于降低。     

乙醇熏蒸对采后油豆角衰老相关生理指标的影响

为探讨乙醇处理调节采后豆角衰老的生理机制,以五常大油豆为试材,采用1.5mL/kg和3 mL/kg乙醇熏蒸油豆角,以清水处理为对照,将处理后的豆角放置于常温(23±1)℃条件下贮藏,研究乙醇对采后豆角衰老相关生理指标的影响。结果表明:外援乙醇熏蒸处理明显降低了贮藏期间油豆角LOX、PPO活性,延缓了膜脂过氧化产物丙二醛(MDA)含量的增加;延迟了CAT和POD活性峰值出现,降低SOD活性,进而显著抑制了超氧阴离子的生成。表明乙醇处理效果存在剂量的差异,1.5mL/kg乙醇熏蒸处理有利于油豆角活性氧的正常代谢,降低膜脂过氧化水平,可延缓豆角贮藏期间的衰老进程。     

不同贮藏温度下薄膜包装油豆角生理特性的研究

研究了25、8、0℃贮藏温度下,薄膜包装油豆角生理特性的变化.结果表明:低温贮藏条件下,薄膜包装油豆角的生理生化变化得到抑制,衰老过程得以廷缓.而0℃贮藏有效抑制了油豆角的呼吸强度、相对电导率的上升速度及丙二醛(MDA)的生成速率,同时降低了过氧化物酶(POD)和过氧化氢酶(CAT)、多酚氧化酶(PPO)的活性,进而使油豆角保持较好的感官品质.     

油豆角的冰温贮藏的研究

本试验研究了塑料小包装的油豆角在室温、冰温、以及经冰点调节剂处理后的冰温贮藏过程中的生理生化变化,探讨了油豆角在贮藏过程中可溶性固形物含量、总糖含量、酸含量、呼吸强度、电导率的变化,并分析了各种变化的原因及相互间的联系;试验结果表明冰温贮藏要比室温贮藏保质期延长15天左右,而山梨糖醇是效果较好的冰点调节剂,同时小包装气调贮藏能够更有效地抑制油豆角在贮藏过程中糖分和水分的消耗,可更大限度延长油豆角的贮藏时间.     

1-MCP处理对油豆角贮藏期间衰老及品质的影响

研究了用不同浓度1-MCP处理对油豆角贮藏期间衰老及品质的影响.结果表明,采用1-MCP(0.5μl/L、1μl/L、2μl/L)处理能够抑制油豆角贮藏期间呼吸作用、乙烯的释放和粗纤维的合成,保持较高的可溶性糖、VC和叶绿素含量,从而有效延缓油豆角的衰老进程并保持良好的品质.但高浓度(2μl/L)1-MCP处理,增加了油豆角贮藏期间腐烂和锈斑的发生.     

生长期及发酵处理对东北油豆角黄酮含量的影响

目的 研究生长期内不同品种油豆角黄酮含量的变化,对金冠豆角种子黄酮种类进行鉴定,并探究发酵处理对金冠种粒中黄酮含量的影响。方法 采用乙醇回流法提取7种东北油豆角总黄酮,通过芦丁比色法检测油豆角种粒及荚皮中的黄酮含量,利用超高效液相色谱-四极杆-飞行时间串联质谱法(ultra performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry, UPLC-Q-TOF-MS)检测豆角中黄酮的种类,最后利用唾液链球菌嗜热亚种和植物乳植杆菌L3对金冠豆粒进行发酵处理,探究发酵处理对金冠豆粒黄酮含量的影响。结果 油豆角中黄酮含量随着生长时期的增加呈现出先上升后下降的变化过程,金冠油豆角粗黄酮中存在白杨素、黄芩黄素、二氢木蝴蝶素A等11种黄酮类物质,发酵处理均会导致金冠种粒的黄酮含量下降。结论 不同品种的油豆角在生长期内黄酮含量的整体变化趋势相似,该研究为油豆角品种选育及产品深加工提供了理论指导。     

发芽处理对蚕豆主要营养成分与抗营养因子的影响

研究发芽处理对启豆2号蚕豆主要营养成分与抗营养因子含量的影响。对蚕豆发芽前后蛋白质、脂肪、淀粉、VC、氨基酸、植酸和单宁含量测定。结果表明：蚕豆在发芽1d时可溶性蛋白质含量显著增加,随后逐渐下降;粗脂肪和淀粉含量均呈下降趋势;发芽2d时VC含量显著增加,达到最大58.65mg/100g,随后逐渐下降,5d后VC含量仍高于未发芽的;发芽后1～2d蚕豆的氨基酸含量略有增加;发芽1d抗营养因子植酸含量下降了33.55%,随后平缓;发芽1d蚕豆的单宁含量增加到462.70mg/100g,2～3d增加比较平稳,5d急剧增加至1306.10mg/100g。可推知,将启豆2号蚕豆发芽1～2d的作为食用及加工的较佳时期。     

Effects of freezing on the organic acid content of frozen green beans and Padrón peppers

HPLC (using a C₁₈ column and water at pH 2.2 as the mobile phase) was used to monitor the quantities of oxalic acid (UV detection at 245?nm) and quinic, malic, citric and fumaric acids (UV detection at 215?nm) of deep-frozen (?22?°C) green beans and Padrón peppers over 12 months. Malic, oxalic and citric acid contents decreased considerably in the first month of frozen storage, then oscillated before returning to those one-month levels after 12 months. The amount of fumaric acid increased, most notably in the peppers. Quinic acid was only detected in the peppers; its content also increased. Freezing the vegetables in vacuum-sealed bags did not moderate these changes. Blanching the beans decreased the quantities of all the acids in the vegetable; then, in most cases, values varied similarly to those of the unblanched beans (notably, the citric acid content of the blanched beans doubled during the first 6–8 months of frozen storage, then fell sharply to roughly its initial, post-blanching level). Overall, blanching and then freezing green beans led to greater losses of their organic acids compared to freezing alone.     

Effects of Vacuum Hydration on the Incidence of Splits in Canned Kidney Beans (Phaseolus vulgaris)

Dry red kidney beans were canned using two different pretreatments: soaking for 12 hr at 20°C, and vacuum hydration for 5 min followed by soaking for 2 hr at temperatures from 45-59.1°C. Samples were then packed, processed to commercial sterility, and tested for percentage of split beans after processing. Vacuum hydration pretreatments greatly decreased the incidence and severity of splitting in the canned product and accelerated water uptake while retaining the same moisture content after soaking as the conventional soak treatment. Vacuum-hydrated beans gained less moisture during retorting than conventionally treated samples.     

多因素交互作用导致烘焙咖啡中绿原酸快速降解

研究烘焙温度、时间及基质pH值对咖啡绿原酸的影响,采用小粒生咖啡豆进行不同程度的烘焙实验,分析不同烘焙温度和时间下pH值、质量损失率、水分质量分数、新绿原酸含量、绿原酸含量、隐绿原酸含量及3 种异绿原酸异构体的变化情况,并建立绿原酸降解动力学模型,采用化学反应模型验证绿原酸单体的降解情况。结果表明,烘焙咖啡中水分质量分数、质量损失率随烘焙温度的升高总体分别呈降低和升高的趋势,随烘焙时间的延长分别呈降低和升高的趋势。绿原酸含量随烘焙温度升高和时间延长显著降低（P＜0.05）,相比生咖啡豆,新绿原酸、隐绿原酸含量随烘焙温度升高先升高后降低,随烘焙时间延长显著降低（P＜0.05）。新绿原酸、隐绿原酸含量与咖啡pH值和烘焙时间呈显著负相关（P＜0.05）,绿原酸含量与烘焙温度、时间呈显著负相关（P＜0.05）,与咖啡水分质量分数呈显著正相关（P＜0.05）。温度和时间的交互作用均对咖啡绿原酸类化合物降解产生高度显著影响（P＜0.001）。绿原酸3 种异构体热降解符合一级反应动力学模型。在化学反应模型中,绿原酸转化为新绿原酸和隐绿原酸两种异构体,3 种异构体质量浓度均随pH值和温度的升高显著降低（P＜0.05）,温度与pH值交互作用对绿原酸降解影响高度显著（P＜0.001）。综上,温度、时间及pH值的协同作用致使烘焙咖啡中绿原酸的快速降解。     

In vitro starch digestibility of fresh and sun‐dried faba beans (Vicia faba L.)

Fresh and sun‐dried faba beans (Vicia faba L.) were cooked, stored for various times at 4 °C and analysed for available starch (AS), resistant starch (RS) and fibre‐associated resistant starch (FARS) contents as well as α‐amylolysis. Fresh beans required a shorter cooking time (25 min) than dried beans (158 min). Cooked fresh faba beans had a higher AS content than cooked dried faba beans. The AS content in both decreased during cold storage, with fresh beans showing a smaller decrease than dried beans with increasing storage time. Cooked fresh faba beans also had a higher total RS content than cooked dried faba beans, although a greater increase in RS content was recorded in the latter upon storage. Starch retrogradation was more prominent in cooked dried faba beans than in cooked fresh faba beans, as indicated by the consistently higher FARS content. The α‐amylolysis rate decreased with increasing storage time, i.e. long‐stored (72 h) cooked faba beans exhibited slower starch digestion, and differences were recorded between fresh and dried beans. The predicted glycaemic index ranged between 60.9 and 58.0% for cooked fresh faba beans and between 57.9 and 55.8% for cooked dried faba beans, which is suggestive of slow glucose release from starch in faba beans. Copyright © 2007 Society of Chemical Industry     

Water sorption and cooking time of red kidney beans (Phaseolus vulgaris L.): part I – Effect of freezing and drying conditions on water sorption and cooking time

Water sorption and cooking time of kidney beans were determined. The beans were manually harvested at 19.2 ± 0.1% moisture content and stored at ?20 and ?10 °C for about half a year. The beans were further dried at 30, 40 and 50 °C inside a thin‐layer drier for 7.5 h or under room conditions for 4 week. The freezing storage temperature before the beans were dried did not influence their cooking time and water sorption. The saturated kernel volumes decreased approximately 7% after drying. The beans decreased their sphericity during water sorption and had a larger swelling ratio in the thickness direction than in other directions. Lower initial moisture content, especially with a higher drying temperature, decreased water sorptivity and resulted in higher percentage of uncooked kernels if the beans were not soaked before cooking. However, there was no relationship between initial moisture content and uncooked percentage if the beans were soaked before cooking. High drying temperature resulted in hard‐to‐cook (HTC) phenomenon.