Effect of Slurry Ice on the Functional Properties of Proteins Related to Quality Loss during Skipjack Tuna (Katsuwonus pelamis) Chilled Storage

The effect of slurry ice on the quality of Skipjack tuna (Katsuwonus pelamis) during chilling storage was investigated and compared to flake ice. Slurry ice‐treated samples showed significantly higher springiness and chewiness variables than the blank and flake ice‐treated samples (P < 0.05). The growth of microorganisms in tuna muscle treated with slurry ice was also down significantly (P < 0.05), and the total aerobic counts didn't reach higher scores than 5.0 log CFU/g during the whole chilling storage. Additionally, the myofibrillar protein, Ca²⁺‐ATPase activity, and total sulfydryl (SH) content in muscle treated with slurry ice were all significantly higher than the blank and flake‐iced samples (P < 0.05). This was probably due to the faster cooling, subzero final‐temperature, and larger heat exchange derived from slurry ice. Standard error of mean and sodium dodecyl sulfate–polyacrylamide gel electrophoresis results also confirmed that slurry ice treatment could effectively retard the degradation of myofibrillar proteins and showed a positive effect on the stability of tissue structures.     

COMPARISON STUDY OF EGG YOLKS AND EGG ALTERNATIVES IN FRENCH VANILLA ICE CREAM

Egg alternatives may replace egg as a functional ingredient in French vanilla ice cream due to their functional and dietary benefits. These egg alternative ingredients include modified corn starch (MCS), whey protein concentrate (WPC) and soy protein isolate (SPI). The objective of this study was to compare the physical and sensory properties of several commercially available egg alternatives in a vanilla ice cream formulation. The SPI exhibited a significantly lower L value compared with the other egg alternatives, whereas the control exhibited a significantly higher b value compared with the other treatments. The apparent viscosity value of MCS was approximately 10-fold greater than the other egg alternatives. There were no significant differences in appearance and mouth-feel among the control, MCS or WPC treatments, whereas SPI exhibited a significantly lower mouth-feel score compared with the other treatments. The control exhibited significantly higher flavor and acceptability scores compared with the other egg alternatives, whereas SPI treatment exhibited least desirable flavor and acceptability. Consumer panelists would purchase the control with the egg alternative formulations.

PRACTICAL APPLICATIONS

The egg alternatives were used to replace egg as a functional ingredient in French vanilla ice cream production. These alternatives can deliver functionality at a lower cost and can be incorporated to produce a suitable ice cream.     

多孔介质中冰成天然气水合物形成实验研究

为了探讨多孔介质中天然气水合物原位形成规律性,进行了将冰粉和石英砂混合并形成天然气水合物的实验研究。实验结果表明,在这种情况下能形成稳定均匀的水合物;冰成天然气水合物的过程是气固反应过程,过程包括吸附、催化、络合、结晶过程。     

改性大豆分离蛋白-磷脂复合物对冰淇淋品质的影响

针对大豆分离蛋白(SPI)取代部分乳粉生产冰淇淋,产品膨胀率低、易融化、口感较硬和有豆腥味等问题,本实验采用超高压改性大豆分离蛋白(USPI)、大豆分离蛋白-磷脂复合物(SPI-PLW)和超高压均质改性大豆分离蛋白-磷脂复合物(USPI-PLW)分别替代乳粉生产冰淇淋,研究了不同改性条件的大豆蛋白对冰淇淋浆料的静态流变学、膨胀率、融化率、硬度和微观结构的影响。通过对比研究得出,以USPI-PLW为原料制作成的冰淇淋的各项标准都优于其它类型的大豆分离蛋白冰淇淋。USPI-PLW冰淇淋融化率为33.17%,膨胀率可达86.86%,较传统低脂冰淇淋融化率降低26.86%,膨胀率提高了94.84%,且储藏硬化后无较大冰晶,相对于传统冰淇淋口感更绵软。     

玫瑰香冰葡萄酒香气成分分析

采用顶空固相微萃取技术(HS-SPME)结合气相色谱-质谱联用法(GC-MS)对云南德钦产区玫瑰香冰葡萄酒中的挥发性成分进行分离测定,共鉴定出71种挥发性香气成分,主要包括酯类、醇类、萜烯类、有机酸及少量醛类、酮类和烷烃.结果表明,酯类、醇类和萜烯类化合物是玫瑰香冰葡萄酒香气的主要构成组分,三者的相对含量占总挥发性香气成分的91.1％;在玫瑰香冰葡萄酒中,酯类化合物相对含量最高,大多数都具有令人愉悦的花果香气,是形成玫瑰香冰葡萄酒浓郁果香的主要香气成分;萜烯类化合物的种类丰富,相对含量较高,且大多数属于单萜醇类,均具有玫瑰香气,可能是形成玫瑰香冰葡萄酒独特玫瑰花香的主要香气成分,其中含量较高的为β-香茅醇、里那醇和橙花醇.     

活性乳酸菌小麦苗汁酸奶冰淇淋的研制

研究了活性乳酸菌小麦苗汁酸奶冰淇淋的生产工艺。结果表明,选用嗜菌、保菌和双歧杆菌混和发酵,加入8%～10%的麦苗汁,选用包括亚麻仔胶在内的复合稳定剂能使得成品风味口感俱佳,膨胀率达90.42%～91.25%,融化率为2.99%～3.08%,活菌数在3个月中保持较高水平。     

麦芽糊精在冰淇淋中增稠稳定作用的研究

本文对不同DE值的麦芽糊精在冰淇淋中增稠稳定作用进行了研究,采用正交试验法确定了麦芽糊精的最佳DE值及用量,同时确定了羧甲基纤维素钠(CMC-Na)、明胶及单甘酯的最佳用量,即DE值10的麦芽糊精用量为7.0%,CMC-Na与明胶的混合物(质量比为1:1)用量为0.4%、单甘酯的用量为0.3%。按此工艺生产的冰淇淋,与按传统配方生产的冰淇淋相比,具有口感细腻、膨胀率理想、抗融性好等特点。     

山药保健冰淇淋的研制

本文以山药为原料制取山药浆,配以其它辅料研制成具有保健功能的冰淇淋.通过正交试验,确定出山药保健冰淇淋的最佳配方,最佳配方为:添加30%山药浆、12%蔗糖、10%奶油、14%奶粉.试验还确定出添加0.25%的抗坏血酸可对山药保健冰淇淋有较为理想的护色效果.