The effect of osmosis pretreatment on hot‐air drying and microwave drying characteristics of chili (Capsicum annuum L.) flesh

Chili flesh pretreated with or without osmotic dehydration (OD) was dried in the hot‐air drying (AD) oven at 50–80 °C or in the microwave drying (MD) oven at 60–180 W. Results showed that the samples osmotically treated in mixed solution (10% salt + 50% sucrose) had the best dehydration effect as compared with single salt or sugar solutions. During the drying process, osmotically treated samples had one falling‐rate period and their effective moisture diffusivities (D_eff) showed a rapidly linear increase with the decrease in moisture content, while directly drying samples showed a three‐phase falling‐rate period and their D_eff increased gradually at the initial period and then rapidly at the final period. When the moisture content decreased, the activation energy increased gradually; however, for AD after OD, it decreased. Among all the processes, MD at 60 W after OD presented the largest vitamin C retention rate and the best colour difference, needing less drying time.     

罗非鱼片的热风微波复合干燥特性

研究了3mm厚的罗非鱼鱼片分别在40℃和50℃的热风温度条件下干燥4h后,又分别于200、400、600W的微波功率下干燥不同时间的干燥速率变化和热风微波干燥对鱼片品质的影响。结果表明,在热风初干温度和时间不变的条件下,当微波干燥时间一定时,罗非鱼片的含水率随微波功率的增大而降低;当微波功率一定时,罗非鱼片的含水率随微波干燥时间的延长呈现先快后慢的速率下降。在热风初干温度不同时,较高的热风温度有利于鱼片在微波干燥阶段的含水率的降低。罗非鱼片在热风微波后的收缩率和复水率随微波功率的升高而增加,当微波功率一定时,收缩率和复水率随热风初干温度升高而增加。而复原率则随微波功率的增加而降低,当微波功率一定时,热风初干温度如果越高,那么复原率越低。     

谷朊粉对马铃薯热干面品质的影响

为提高马铃薯热干面的品质和稳定性,该文在分析谷朊粉基本成分与物化特性的基础上,深入研究了谷朊粉添加量对混合粉特性及对生鲜及熟制马铃薯热干面蒸煮、质构、贮藏等品质特性的影响.结果表明,随着混合粉中谷朊粉含量升高,其持水性下降,吸水膨胀性上升.随着谷朊粉添加量的增加,马铃薯热干面吸水性呈下降趋势、蒸煮损失率呈先上升后下降变...     

酱油熟料的微波加压灭菌研究

采用微波加压灭菌酿造酱油熟料的技术方法是可行的,它具有时间短、灭菌效率高、微波功率和灭菌时间容易精确控制的优点,更容易在实现酱油孰料的完全灭菌的同时,最大限度地提高酱油孰料的消化率。     

Comparison of microwave and high-pressure processing on bound phenolic composition and antioxidant activities of sorghum hull

The influence of microwave boiling (MB treated 5, 10 and 15 s was abbreviated as MB5, MB10 and MB15, respectively) and high-pressure boiling (HB processed 10, 20 and 30 min was denoted as HB10, HB20 and HB30, respectively) processing on the composition and content of bound phenolic substances of sorghum hull and their antioxidant capacity were evaluated. Nine bound phenolic profiles were identified by HPLC-ESI-MS/MS, including syringic acid, veratric acid, p-hydroxybenzonic acid, caffeic acid, sinapic alcohol, ascorbic acid, prenylnaringenin and luteolin. Compared with traditional hot water processing (HP treated 10, 30 and 50 min was abbreviated as HP10, HP30 and HP50, respectively), the content of free procyanidins and total phenolics of sorghum hull treated with HB increased by 35.92–58.87% and 6.20–18.70%, respectively. Sorghum hull treated with HB20 possessed the highest ABTS (ABTS radical scavenging capacity) and FRAP (ferric ion reducing antioxidant power) among all treatment groups.     

Effect of blanching and drying treatments on quality of bamboo shoot slices

The enzymes activity, texture, pectin, microstructure and colour change in bamboo shoots (Dendrocalamus latiflorus) were examined to evaluate the effect of blanching and drying treatments on quality of bamboo shoot slices (BSS). Peroxidase (POD), phenylalanine ammonia‐lyase and polyphenol oxidase in BSS will become completely inactive at 95 °C for 6‐, 9‐ and 12‐min blanching treatments, respectively. The hardness and protopectin (PP) content decreased after the blanching treatment. Meanwhile, the content of water‐soluble pectin increased initially and then decreased gradually during the blanching. After the blanching treatment, the L* and a* of BSS decreased, while b* increased, ΔE > 2. The hardness of rehydrated BSS decreased by 43.57% after freeze drying (FD), which, however, decreased more after hot air drying (HAD). The pectin of rehydrated BSS was also determined to explain the hardness change in BSS. The BSS acquired similar microstructure of fresh samples after FD, while microstructure of BSS was severely damaged after HAD. The colour of BSS changes significantly after drying treatment. However, FD can maintain better colour of BSS than HAD. The results may provide a reference for industrial production of BSS.     

不同预处理方式对西兰花等外品热风干燥粉体性质的影响

为明确西兰花等外品热风干燥制粉工艺适宜预处理方式,分别采用蒸汽蒸制、热水烫漂、切小丁的预处理方式制备西兰花等外品热风干燥粉体(the hot air drying powder of broccoli defective product,简称HBD粉),研究了不同预处理方式对HBD粉粉体性质的影响。结果表明:烫漂对HBD粉色泽保持效果最好,V_C保留量较高,但溶解性较差。烫漂10 s粉体流动性较差。烫漂30 s粉体较难吸湿,更利于压片成型和干燥保存;蒸汽蒸制粉体水溶性指数较大。蒸汽10 s粉体平均粒径最小,流动性较差,总糖、还原糖含量最高,吸湿能力最强,达22.8%。蒸汽30 s更利于压片成型;小丁粉体膨胀力、持水力较强。经烫漂10 s、蒸汽10 s预处理的HBD粉适宜作为功能配料添加到食品中或吸附于食品表面,经烫漂30 s、蒸汽30 s预处理的HBD粉体适宜片剂、胶囊等产品剂型加工。     

420t/d废纸脱墨处理系统的生产工艺及运行

介绍了从国外引进的利用100%废纸生产胶印新闻纸的废纸脱墨生产线，从主要工艺装备的技术参数，工作原理及化学药品的选择等方面作了具体论述，并对使用情况，存在问题等进行探讨。     

电子鼻结合顶空SPME-GC-MS联用技术分析贵州不同品种辣椒发酵后挥发性成分

以贵州5种不同辣椒品种为研究对象,采用电子鼻技术,结合顶空固相微萃取-气相色谱-质谱（solid phase microextraction-gas chromatography-mass,SPME-GC-MS）联用技术,对其发酵后挥发性成分进行分析。结果表明,电子鼻分析结果能够很好地区分不同辣椒品种发酵后的风味;采用主成分分析（principal component analysis,PCA）以及线性判别分析（linear discriminant analysis,LDA）可知,PCA和LDA主成分贡献率总和分别为99.93%、99.19%,均大于95%,说明传感器识别效应和样品间的风味区分度较好。SPME-GC-MS分析结果表明,5种样品共检出124种不同的挥发性风味物质。其中黄平线椒占97种,以酯类物质相对含量最高,为36.82%;施秉线椒和大方皱椒分别占88种和94种,且均以醇类物质相对含量最高,分别为31.88%、28.99%;百宜平面椒和花溪党武辣椒分别占89种和71种,均以烃类物质相对含量最高,分别为26.75%、35.08%。此结果与电子鼻PCA和LDA结果相一致。因此,通过SPME-GC-MS和电子鼻分析结果可知,电子鼻能够很好地区分贵州名优产地不同辣椒品种发酵后的风味。