Effect of pulsed electric fields on cricket (Acheta domesticus) flour: Extraction yield (protein,fat and chitin) and techno-functional properties

Edible insects are an important source of proteins, fat, and chitin, which need to be extracted to develop tailored products with a controlled composition. Pulsed electric fields (PEF) is a non-thermal technology that can enhance the extraction. This study explores the effect of PEF on the extraction of protein, fat and chitin from cricket flour, as well as the material's functional properties. House crickets (Acheta domesticus) were treated with PEF at several conditions (4.9–49.1 kJ/kg). PEF treatment with 4.90 kJ/kg increased the extraction yields of protein (>18%) and fat >40%), while the treatment at 24.53 kJ/kg increased the oil binding and emulsifying capacity and antioxidant activity of the cricket flour by 28.10, 64.88 and 58.20%, respectively. Water binding capacity and foaming capacity were not affected by the PEF treatment. These results outline PEF as a suitable pretreatment for the valorization of house cricket biomass with possible industrial application.     

Consumer attitudes toward dairy products from sheep and goats: A cross-continental perspective

This study aimed to assess consumer knowledge, attitudes, and perceptions toward dairy products from sheep and goats. A web-based survey was conducted in Latin America (Mexico and Chile), Europe (Italy, Spain, Greece, and Denmark), and Asia (Bangladesh). From March to June 2021, adult participants answered an online survey available in 5 languages. In total, 1,879 surveys were completed. Categorical and ordinal data were analyzed as frequencies and percentages. To determine the relationship between the variables for purchasing and consumption behaviors of respondents who declared that they consume dairy products, a multiple correspondence analysis was carried out. Most completed surveys were from Mexico and Italy (30% and 33.7%, respectively). Most respondents were between 18 and 29 yr old, female, highly educated, and employed. The majority of respondents (70.8%) declared that they consume dairy products from small ruminants. Consumers preferred products from both sheep and goats (49.4%); however, it was observed that in Mexico, Denmark, and Bangladesh, more than 50% preferred goat dairy products. The most-consumed products were mature and fresh cheeses. Mature cheese was the most-preferred product in Chile; in Mexico, Italy, Greece, and Denmark, it was fresh cheese. Unlike the rest of the countries, in Bangladesh, dairy product consumption from small ruminants was observed by more than 30% of respondents. In Mexico, a higher percentage of people do not consume sheep or goat dairy products because they are unfamiliar with them. In Mexico, Chile, and Bangladesh, limited market availability was also a variable responsible for nonconsumption. In European and Asian countries, sheep and goat dairy products are not consumed because consumers dislike them, in addition to a greater awareness of sustainability and climate change issues. The multiple correspondence analysis defined 5 dimensions. Dimension 1 was associated with the geographic location of the respondent (country and continent), the type of milk (sheep or goat), and the consideration of well-being and health as characteristics associated with the consumption of dairy products from small ruminants. Dimension 2 was associated with the respondent's country of origin and the frequency of consumption. Dimension 3 was associated with gender, education, and employment status. Dimension 4 was associated with the respondent's age, the association of the “healthy” concept of sheep and goat dairy products, and the consideration of the nutritional benefits of dairy as responsible for considering them healthy. Dimension 5 was associated with a “strong smell and taste” of sheep and goat dairy products. This study showed that consumer attitudes toward dairy products from sheep and goats vary between continents. In conclusion, results showed consumer interest in animal welfare and environmental impact issues related to small ruminant farming as well as a general attraction to local products. It seems that these factors contribute to consumers' perception of the quality of dairy products, so the industry and select farmers should carefully consider incorporating them into their supply chain.     

Consumer Perception of Cultured Yellow Perch (Perca flavescens) and Its Market Competitors

ABSTRACT:  Aquaculturists are concerned with performance of cultured yellow perch against its wild-caught market competitors. In this study, consumer perception of cultured yellow perch was compared to that of wild-caught walleye, ocean perch, and zander. In 2 experiments, species were ranked for preference, rated for liking, and rated for degree of difference from a reference (cultured perch). Results were analyzed using Friedman's analysis of ranks, analysis of variance, and method of maximum likelihood. In Experiment 1 ( n = 50), there was no significant difference in preference or liking, and all wild-caught species were significantly different from the reference. In Experiment 2 ( n = 68), the species were trimmed to the same thickness for a more fair comparison of these species. Cultured yellow perch was equally preferred to all species but was rated significantly higher than walleye in overall liking. In addition, ocean perch and walleye were found to be significantly different from cultured perch, while zander was not.     

UHT纯牛奶消费喜好和关键感官特性的关联分析

以14种市场上不同类型超高温（Ultra-high temperature,UHT）纯牛奶为研究对象,采用9点喜好标度、适合项勾选法（Check-All-That-Apply,CATA）和恰好标度,同时结合偏最小二乘回归分析（PLS）分析不同类型UHT奶消费喜好和关键感官特性接受性差异。研究表明：不同类型UHT奶的整体喜好值范围为4.07~6.25,脱脂奶和部分全脂奶的喜好值最低（<5）,全脂和低脂奶的整体喜好差异不显著（p>0.05）。不同类型UHT奶的乳香、甜味、余味、浓稠和爽滑5个关键感官特性接受性上存在显著差异（p<0.05）,通过PLS回归模型筛选出导致消费喜好差异的7个关键感官特性接受性指标,分别为余味、乳香、甜味、浓稠、爽滑（-）、甜味（-）和乳香（-）。甜味和乳香偏弱以及爽滑度不够是分别导致低脂奶和部分全脂奶样品整体喜好偏低的关键感官特性。相关研究旨在为后期UHT纯牛奶消费喜好和产品感官品质研究提供基础理论和数据参考。     

Contribution of the starch, protein, and lipid fractions to the physical, thermal, and structural properties of amaranth (Amaranthus caudatus) flour films

ABSTRACT:  Amaranth protein–lipid (PL) and protein (P) films were elaborated and compared with amaranth flour films in order to determine the contribution of the interactions between the biopolymer (starch and protein) and the lipids to the film properties. The films were made by the casting method, using the same glycerol concentration (0.9 g glycerol/100 g solution). A separation of the lipid fraction in the PL films and a polymorphic transformation of the corresponding fatty acids were observed by differential scanning calorimetry (DSC) and verified by an analysis of the microstructure by scanning electron microscopy (SEM). The flour films showed no separation of the lipid fraction, evidence that the lipids were strongly associated with the proteins and homogenously distributed throughout the starch network, contributing to the good mechanical properties when compared to the PL films and to the excellent barrier properties when compared to both the PL and P films. The protein-protein interactions also contributed to the mechanical properties of the flour films. The presence of proteins and lipids in the flour films had an important effect on film solubility, and also on the color and opacity of the films. This study showed that the flour film properties depended on the interactions formed by their polymers (starches and proteins) and by the lipid, on the distribution of these interactions within the film matrix and on the concentrations of each component in the film.     

Chemical and nutrient content of corn (Zea mays) before and after being flame roasted

Samples were collected before and after corn (Zea mays L) was flame roasted on several farms in southwestern Ontario. Seven sources of corn were sampled during one field trip and three during another. After passing through a propane flame, the roasted corn was cooled to ambient temperature within ～ 15 min. All samples were ground (1 mm screen) and analysed. The true metabolisable energy, corrected to zero N balance (TME_n), true available amino acids (TAAA) and true DM digestibility were determined on the first collection of samples using adult White Leghorn cocks. The temperature of the corn as it left the roasting unit ranged from 110 to 140°C. The dry matter content was higher (P < 0.05) and the 100-kernel weight and mould count were lower (P < 0.01 and P < 0.05, respectively) for the roasted than for the non-roasted corn. Among the seven sources the N content of the roasted corn was higher (P < 0.05) than that of the non-roasted corn; among the other three sources the N content was similar. The zearalenone and free ergosterol contents were lower in the roasted than in the non-roasted corn, though the differences were not significant (P > 0.05). Roasting had little or no effect on TME_n, TAAA and true dry matter digestibilities or on the carbohydrate and fibre fractions of the corn samples. These and other reported data indicate that flame roasting of corn is an effective procedure for the removal of moulds without affecting the nutrient content and bioavailability of the roasted material.     

当归愈伤组织褐化前后生理生化的研究

通过测定硝酸还原酶活力、可溶性蛋白质含量、还原糖含量以及丙二醛的含量来研究当归愈伤组织褐化前、后生理生化指标的变化;结果表明褐化对当归愈伤组织的活性影响显著。