花生壳水溶性膳食纤维不同提取工艺及其抗氧化活性研究

以花生壳为原料,经粉碎过筛后,采用一次酸提、二次酸提、三次酸提、微波提取和超声波提取等方法提取其中的功能性成分之一--水溶性膳食纤维(SDF),测定每种方法的提取率和所得到的SDF 中的非淀粉性多糖(NSP)的含量,并计算它们的综合评分。结果表明：在这五种提取方法中,三次酸提的提取率最大,微波提取的SDF 中NSP 的百分含量最大,综合评分是三次酸提最大。同时,还研究了SDF 的铁还原力、钼还原力、清除DPPH 自由基、超氧阴离子自由基和羟自由基等五种抗氧化活性。     

The effect of extrusion cooking using different water feed rates on the quality of ready-to-eat snacks made from food by-products

The effect of different levels of feed moisture (12–17%) during extrusion cooking, using a co-rotating twin-screw extruder on selected nutritional and physical properties of extruded products was investigated. Four different formulations were used based on wheat flour and corn starch with the addition of 10% brewer’s spent grain (BSG) and red cabbage (RC) trimming reducing the flour and starch. The samples were: wheat flour + BSG (WBSG), corn starch + BSG (CBSG), wheat flour + red cabbage (WRC) and corn starch + red cabbage (CRC). Process conditions utilised were: constant feed rate of 25 kg/h, screw speed 200 rpm and barrel temperature of 80 and 120 °C. The results indicated that increasing the water feed to 15% increased the level of total dietary fibre (TDF) in all the extrudates while extrusion processing increased the level of TDF in WBSG, CBSG and CRC but decreased in WRC products. Extrusion cooking increased the level of total antioxidant capacity (TAC) and total phenolic compounds (TPC) in WRC and CRC. In addition to water feed level affecting the TDF of the extrudates, also affected were the expansion ratio, bulk density, hardness, WSI, SME and colour. The protein level of the products and hardness of extrudates were related to the different formulations.     

响应面法优化猕猴桃皮渣可溶性膳食纤维提取工艺

以猕猴桃皮渣为原料,采用酸水解法从猕猴桃皮渣中提取可溶性膳食纤维。通过单因素试验和响应面分析法,考察料液比、浸提液pH 值、提取温度、提取时间对可溶性膳食纤维提取率的影响,优化提取工艺参数。结果表明,酸水解法提取猕猴桃皮渣可溶性膳食纤维的最佳提取工艺条件为料液比1:37(g/ml)、浸提液pH2.5、提取温度80℃、提取时间100min,在该条件下可溶性膳食纤维的得率为47.74%。     

基于Transformer实现文本导向的图像编辑

为方便非专业用户修图,提出一种基于Transformer的图像编辑模型TMGAN,使用户可通过自然语言描述自动修改图像属性。TMGAN整体框架采用生成对抗网络,生成器采用Transformer编码器结构提取全局上下文信息,解决生成图像不够真实的问题;判别器包含基于Transformer的多尺度判别器和词级判别器两部分,给生成器细粒度的反馈,生成符合文本描述的目标图像且保留原始图像中与文本描述无关的内容。实验表明,此模型在CUB Bird数据集上,IS（inception score）、FID（Fréchet inception distance）以及MP（manipulation precision）度量指标分别达到了9.07、8.64和0.081。提出的TMGAN模型对比现有模型效果更好,生成图像既满足了给定文本的属性要求又具有高语义性。     

中国马铃薯主食化面临的问题及解决方法

农业部宣布马铃薯将成为中国新的主食,马铃薯块茎富含淀粉,高品质蛋白、重要维生素、矿物质和微量元素,然而,将马铃薯升级为中国的主食需要从文化、技术、环境和经济等方面解决很多问题。克服这些困难需要借鉴国内外的经验和技术,以牺牲生态环境为代价扩大马铃薯种植面积是不可取的。内蒙古、西北和西南地区作为中国马铃薯主产区,不适合继续扩大马铃薯种植面积,因为已经导致了草原荒漠化和水土流失等问题,政府已经提出要退耕还草或者退耕还林。在中国南部,利用冬闲田种植马铃薯,是最值得推崇的增加中国马铃薯产量的方法,也是最值得政府推广的方法。另外,将马铃薯开发成中国特色的主食如面条和馒头,使用脱水马铃薯泥作为半成品原料,提高马铃薯块茎的干物质含量,采用低温干燥方式将马铃薯加工成半成品原料等技术问题需要解决。     

竹笋膳食纤维理化特性及改性技术研究进展

改性技术对竹笋膳食纤维(Bamboo shoot dietary fiber,BSDF)理化性质和生理功能的影响是BSDF开发利用的研究重点。本文概述了BSDF的理化性质,总结了生物酶、发酵、挤压、超微粉碎、超声波、微波、高速剪切、微胶囊化、高温蒸煮及动态高压微射流等技术对BSDF的影响,分析了BSDF开发利用不足和目前BSDF加工技术研究存在的问题,对利用现代加工技术和理论高效制备BSDF的研究方向进行展望,为BSDF产品的开发利用及其工业化生产提供参考。     

Synthetic colourings of some snack foods consumed by primary school children aged 8–9 years in Hong Kong

An HPLC method with photodiode array detection was used for the quantification of 11 synthetic dyes in 87 snack food products commonly consumed by children in Hong Kong, China. Dietary exposure to synthetic colours was estimated using food-frequency questionnaire data obtained from 142 primary school children aged 8–9 years in three districts of Hong Kong. Dietary exposure to synthetic colours for an average primary school student was considerably lower than the threshold for acceptable daily intake (ADI) for their ages, except for sunset yellow FCF. Data obtained showed that the average daily intake of sunset yellow FCF (E110) was 51% over the ADI threshold in 9-year-old boys. The higher intakes of sunset yellow FCF were mainly due to the high consumption of soft drinks and desserts such as jellies, which have high concentrations of this synthetic colour additive.     

超声波辅助提取火龙果皮中水溶性膳食纤维工艺研究

采用超声波辅助提取火龙果皮中水溶性膳食纤维(SDF),通过单因素实验和响应面分析,探讨提取时间、提取温度、p H、液料比、超声波功率五个因素对SDF得率的影响,并对提取工艺条件进行优化。结果表明,超声波辅助提取火龙果SDF的最佳工艺条件为超声波功率400 W、提取温度67℃、提取时间50 min、p H3.3、液料比20∶1(m L/g),然后采用95%的乙醇沉淀2 h,4000 r/min离心20 min后用75%乙醇洗涤沉淀,SDF得率达26.45%。该工艺可以有效地从火龙果皮中提取水溶性膳食纤维。      

超声协同酶法提取杏鲍菇中可溶性膳食纤维及抗氧化活性研究

以杏鲍菇为原料,采用超声协同酶法提取杏鲍菇中可溶性膳食纤维,探讨超声功率、超声时间、料液比、酸性纤维素酶和酸性蛋白酶加酶量对可溶性膳食纤维得率影响,通过正交实验优化提取工艺条件,并对其抗氧化活性进行研究。结果表明,超声协同酶法提取最佳工艺条件为:酸性纤维素酶1.5%、酸性蛋白酶3.0%、时间25min、功率200W、料液比1∶35,杏鲍菇中可溶性膳食纤维提取率为12.52%±0.22%。杏鲍菇中可溶性膳食纤维对·OH、·O2-和DPPH均表现出较强的清除力,在一定浓度范围内,清除率随浓度增大而升高,·OH 0.6mg/m L清除率为76.22%,·O2-0.7mg/m L清除率为74.18%,DPPH 0.6mg/m L清除率为76.15%,其对NO2-有一定的清除作用,0.7mg/m L清除率为62.70%,但其清除能力均低于VC。      

CO2辅助挤压对马铃薯渣可溶性膳食纤维的影响

以马铃薯渣为原料,研究CO2辅助挤压各工艺条件对马铃薯渣可溶性膳食纤维的影响。结合马铃薯渣颜色、持水力、持油力和膨胀力的变化,得出CO2辅助挤压最佳工艺参数为:CO2发生剂柠檬酸与碳酸氢钠添加质量比为1∶1、添加量30%(质量分数)、挤压温度185℃、物料含水量25%(质量分数)、螺杆转速170 r/min。在此工艺条件下,挤压所得马铃薯渣可溶性膳食纤维含量较高,色泽较好,水合特性得到较好地保持,可为马铃薯渣膳食纤维的改性提供参考。