籼米淀粉超微粉体的理化性质

生物技术和机械粉碎相结合的方法获得了超微粉体,探讨了超微粉体的糊化特性、溶解性和膨润力等理化性质。采用Sepharose CL-2B凝胶色谱分析技术研究了相对分子质量的变化趋势。     

Effects of superfine grinding on physicochemical and antioxidant properties of Lycium barbarum polysaccharides

The objective of this study was to investigate the effects of superfine grinding on the physicochemical and antioxidant properties of Lycium barbarum polysaccharides (LBP). Superfine grinding treatment could decrease the average molecular weight (changed from 834.0, 85.2 and 70.6 to 538.5, 71.2 and 2.1, respectively), the spherical particle’s heights (changed from 0.86, 0.59 and 0.51 nm to 0.74, 0.55 and 0.43 nm, respectively) and the spherical particle’s diameter (changed from 98.33, 70.67 and 86.33 nm to 88.67, 47.67 and 51.33 nm, respectively) of LBP. After being superfine grinding treated, the ΔH values of LBP changed from −154.6, −136.5 and −105.0 J/g to −220.8, −97.2 and −46.5 J/g, respectively. The IC₅₀ of LBP from treated materials on DPPH radical (4.96, 1.98 and 2.97 mg/mL) and ABTS radical (2.25, 0.20 and 0.25 mg/mL) were extremely lower than those of LBP from untreated materials. The results suggested that superfine grinding treatment enhanced LBP’s antioxidant activities. Molecular weight and solution behavior were key factors in polymer’s antioxidant activities.     

超微粉碎对菠萝蜜超微全粉品质的影响

为了明确超微粉碎工艺对菠萝蜜粉品质的影响,本文以真空冷冻-变温压差膨化联合干燥的菠萝蜜粗粉为原料,研究了超微粉碎时间对菠萝蜜超微全粉的各项理化和营养品质的影响。实验结果表明,超微粉碎时间对菠萝蜜的粒径的影响较小,经5min粉碎后即可达到超微粉的要求;菠萝蜜粉的溶解性指数和持水力与超微粉碎时间呈上升趋势,类胡萝卜素和维生素C含量与超微粉碎时间呈下降趋势;通过真空冷冻-变温压差膨化联合干燥方法干燥法获得的菠萝蜜粉的流动性可满足实际生产的需要,产品的吸湿性较小,不易粘结。      

The effect of superfine grinding on physicochemical properties of three kinds of mushroom powder

The effects of superfine grinding on apparent structure, physicochemical properties, and functional characteristics of three kinds of mushroom (Lentinus edodes, Hericium erinaceus, and Cordyceps militaris) powders were investigated. Coarse and 100-mesh powders of the mushrooms were prepared by common grinding, while a superfine powder was obtained by superfine grinding. By comparing the mushrooms before and after grinding, it was found that the mushroom fines did not produce new chemical groups but increased crystallinity. The results of the physicochemical properties revealed that the fines became less fluid after grinding. The protein content and solubility increased as the particle size decreased. The water and oil holding capacity, glucose binding capacity, cation exchange capacity, and antioxidant activity of the mushroom fines increased after grinding. This study provides a theoretical basis for the development process of edible mushroom food, as well as new ideas for the development of edible mushrooms.     

鲢鱼骨中油脂提取方法的研究

目的 研究鲢鱼骨中鱼油的提取最佳工艺。方法 对比高温蒸煮、热风干燥、冷冻干燥不同处理方式, 将鲢鱼骨粉碎后, 以提取率为指标, 分别研究索氏提取、稀碱水解、酶法水解三种鱼油的提取方式, 并对稀碱水解法进行正交实验方案设计。结果 综合考虑, 采用稀碱水解法提取具有较高的应用价值。稀碱水解法的最优条件为温度85 ℃、pH10.0、料液比1:2、时间40 min, 鲢鱼骨油提取率为39.83%。结论 采用热风干燥法对鱼骨进行前处理, 稀碱水解法提取鲢鱼骨中脂肪提取率最高。     

超微粉碎对甜荞麦麸皮物理特性影响

采用超微粉碎的方法处理甜荞麦麸皮,研究超微粉碎对甜荞麦麸皮持水力、持油力、膨胀力、可溶性膳食纤维、阳离子交换能力等性质影响,并比较不同粒度的超微麸皮粉性质的变化,结果表明,甜荞麦皮粉经超微粉碎之后,其持水力,膨胀力,可溶性膳食纤维含量和阳离子交换能力都有很大的提高,持油力略有提高,超微粉碎频率为20 Hz时制得的微粉C(粒径≤16.34μm)综合指标最佳。     

鲽鱼骨超微细鱼骨泥的加工工艺研究

以鲽鱼骨为原料,采用高精密湿法超微粉碎技术制备微细鱼骨泥,研究微细鱼骨泥的较优加工工艺,为鱼骨高值化利用提供生产性指导和参考。结果显示,鲽鱼骨微细骨泥加工过程中,粉碎方式、粉碎次数、冰水添加量对鱼骨泥的粒径、感官品质、出料温度、钙元素溶出量均具有显著影响。粉碎程度越大,鱼骨泥粒径越小,钙元素溶出量越高。较优的鱼骨泥的加工工艺为:胶体磨细粉碎时冰水添加量为骨泥与冰水比例1：3 (w/v),超微粉碎时冰水添加量为骨泥与冰水比例1：5 (w/v)、超微粉碎次数为2次。该工艺条件下可获得100目的微细鱼骨泥,且得率达到60.57%。制得的微细骨泥蛋白质含量较高,脂肪含量较低,钙磷比接近2：1,营养物质均衡丰富,且TVB-N和菌落总数符合相应标准要求。     

冻藏对鲢鱼、鲤鱼鱼肉质构影响的比较研究

比较冻藏处理对鲢鱼、鲤鱼鱼肉质质构的影响.采用质构仪对冻藏的鲢鱼、鲤鱼鱼肉进行测定,并与未经冻结的鱼肉指标值进行比较.结果表明,经过冻结的鲤鱼、鲢鱼的硬度、弹性、黏附性、咀嚼性、恢复性等指标值均有所下降,下降幅度不同,与鲤鱼相比较,鲢鱼质构变化明显.     

超微粉碎对红小豆全粉物化特性的影响

以红小豆粗粉为研究对象,通过高频振动超微粉碎处理,研究振动式超微粉碎技术对红小豆全粉物化特性的影响。结果表明:随着超微粉碎时间的延长,红小豆微粉的平均粒径进一步减小,微粉颗粒大小更均匀,颜色更白亮,更均匀。与粗粉相比,红小豆微粉的休止角和滑角均增大,松装密度和振实密度均小于粗粉。超微粉碎处理可以显著改善红小豆全粉的颗粒均匀性、颜色均匀性、吸湿性、溶胀度、溶解性等物化特性。     

杜仲叶超微粉馒头制备工艺及品质特性分析

目的 优化杜仲叶超微粉馒头制备工艺,并对其品质特性进行分析。方法 以馒头感官评分及质构特性为考量指标,以杜仲叶超微粉添加量、酵母粉添加量、水添加量为影响因素进行单因素试验;在此基础上,采用响应面试验优化杜仲叶超微粉馒头的制备工艺。结果 最优工艺条件:杜仲叶超微粉添加量1.3%、酵母粉添加量1.6%、水添加量49%。按此工艺制备得到的杜仲叶超微粉馒头的感官评分为95.33±0.83分。各因素对杜仲叶超微粉馒头品质的影响顺序为:杜仲叶超微粉添加量>酵母粉添加量>水添加量。馒头的质构特性表明:添加杜仲叶超微粉后馒头硬度、胶黏性、咀嚼性及黏度均显著优于对照组(P<0.05)。结论 优化后杜仲叶超微粉馒头营养丰富,且具有杜仲叶独特的风味,有较大的应用潜力。     

白鲢鱼肌肉脂肪氧合酶提取条件优化及酶学性质研究

本文以白鲢鱼肌肉为原料,通过单因素实验对白鲢鱼肌肉脂肪氧合酶(LOX)提取条件进行优化;用圆二色谱法和荧光光谱法对其贮藏稳定性、热稳定性、最适p H进行研究;探讨磷酸盐缓冲液p H、离子强度、二硫苏糖醇(DTT)和乙二胺四乙酸(EDTA)添加量对白鲢鱼肌肉LOX提取工艺的影响。结果表明,白鲢鱼肌肉LOX适宜提取条件为磷酸盐缓冲液p H7.8、离子强度50 mmol/L、EDTA和DTT添加量均为2 mmol/L,在此条件下提取白鲢鱼肌肉LOX的酶液浓度为(1.98±0.037)mg/m L,活力为(244.44±5.93)U。通过对LOX酶学性质研究可知,白鲢鱼肌肉LOX在常温条件下0~2 d内酶活性较为稳定,最适作用温度为40℃,最适p H为7.8。      

Gel properties of surimi from silver carp (Hypophthalmichthys molitrix) as affected by heat treatment and soy protein isolate

The effects of setting conditions and soy protein isolate (SPI) on textural properties of surimi produced from silver carp were investigated. Effects of setting temperature, setting time and protein concentration on the gel strength were evaluated and compared utilizing response surface methodology. Models for breaking force and breaking distance of silver carp surimi were established. The total protein content was 13.4% in all experimental samples. Setting temperature and protein concentration were the major factors affecting the gel strength. In the range of the additive SPI protein (10–40%), breaking force and distance of silver carp surimi gels decreased when the protein ratio of SPI was increased in the total protein at 30 and 40 °C for 60 min setting and heating at 85 °C for 30 min, but the breaking force obtained for 90% surimi protein plus 10% SPI protein was higher than surimi alone at 50 °C for 60 min incubation and heating at 85 °C for 30 min.     

Effect of glucono-δ-lactone acidification and heat treatment on the physicochemical properties of silver carp mince

The physicochemical and rheological properties of silver carp mince with different levels of glucono-δ-lactone (GDL) with or without heat treatment at 90 °C for 20 min were investigated. Breaking force, deformation, and whiteness of GDL-induced gels increased with increasing GDL concentration. Heat treatment of GDL-induced gels led to a significant increase in breaking force and whiteness, but decreased deformation. Disulphide bond formation was observed in GDL-induced gels, which increased after heating of the acidified gels. Solubility profiles of gels in different solutions suggested that gel networks were mainly due to hydrophobic interactions, although other chemical interactions may also occur. SDS-PAGE showed that acidification resulted in a large decrease in myosin heavy chain (MHC) band intensity, suggesting the extensive formation of covalent cross-links among silver carp myosins during GDL-induced gelation.     

白鲢鱼骨汤酶解工艺的研究及风味分析

以白鲢鱼骨高压熬制而成的鱼骨汤为原料,选择中性蛋白酶对鱼骨汤进行酶解,以水解度为指标,通过单因素实验和正交设计确定中性蛋白酶水解鱼骨汤的最佳工艺条件;并对酶解前后骨汤中的挥发性成分和游离氨基酸含量进行比较。结果表明:鱼骨汤酶解的最优条件为酶添加量2000U/g,起始pH6.5,酶解温度50℃,酶解时间3h。此条件下酶解的水解度能达到24.04%;酶解前后骨汤中的腥味挥发性成分含量降低,呈鲜香味游离氨基酸含量增高,鱼骨汤中的鱼腥味明显减小,风味得到较大改善。      

Protein and silver nitrate interaction during finer wool production: enhancing tensile properties along with synthesis of nano silver

The simultaneous in situ synthesis of silver nanoparticles and slenderizing of wool fibers was carried out in one single step process without using external reducing agent. The functional groups of wool fibers were responsible for the reduction of silver ions into silver nanoparticles, and the possible interactions between the synthesized nanoparticles and the protein chains of wool fibers have been thoroughly discussed. According to the hypothesized mechanism, which was further proved by UV–vis absorption spectra, there is also a possibility of cross-linking formation within wool protein chains through diazotion reaction with amine groups of wool fibers. Duration of the process at the applied temperature allowed enough time for complete growth of the silver nucleus inside the protein chains, creating more cross-linking within the protein chains of wool fibers. Findings suggest the potential of the proposed method in producing fine wool fibers with enhanced tensile strength and slight color change.     

Seasonal differences in the properties of gelatins extracted from skin of silver carp (Hypophthalmichthys molitrix)

The gelatins were extracted from skins of silver carp (Hypophthalmichthys molitrix) caught in winter and summer, respectively. The physicochemical (molecular weight distribution and melting point) and rheological characteristics (viscosity property), as well as functional properties (emulsifying capacity and stability) of the gelatin from winter silver carp skin were compared with those of the summer equivalent. The results showed the properties of the summer gelatin were superior to those of the winter one, showing higher viscosity, emulsion stability, melting point and lower concentration for gelling. The summer gelatin has slightly denser strands of the gel microstructure which was observed by scanning electron microscopy (SEM). Different properties of gelatins from skin of silver carp may be attributed to the big discrepancy of the environmental temperature in the two seasons.