Optimization of enzymatic hydrolysis of Pleurotus ostreatus derived proteins through RSM and evaluation of nutritional and functional qualities of mushroom protein hydrolysates

Pleurotus ostreatus (Jacq.) P. Kumm., the second most widely cultivated oyster mushroom was grown on paddy straw, which is cheap and readily available waste material. After harvesting and drying, nutritional, and antinutritional composition of P. ostreatus were estimated using the standard assay methods. Tannin and phytic acid were present in very negligible amount (0.095 ± 0.027 mg/g and 0.150 ± 0.083 mg/g, respectively), whereas oxalate and cyanide were absent in whole mushroom. In fact, P. ostreatus was hydrolysed with commercially available proteinase K, pepsin and trypsin with different concentrations of the enzymes (0.05%, 0.10% and 0.15%), at different temperatures (30 °C, 40 °C and 50 °C) for different time periods (60, 90 and 120 min) to get the mushroom protein hydrolysates. Degree of hydrolysis and protein content varied from 4.29 ± 1.12% to 99.42 ± 0.02% and from 0.25 ± 0.07 mg/mL to 3.22 ± 0.12 mg/mL, respectively. Maximum degree of hydrolysis and the highest protein content of protein hydrolysate was obtained when using 0.15% proteinase K, at 50 °C for 120 minutes. Mushroom protein hydrolysates thus obtained exhibited improved functional characteristics such as foaming capacity, foaming stability and emulsifying property than the unhydrolysed mushroom. Based on the result of the present study, the mushroom protein hydrolysates could be served as useful ingredient for food and nutraceutical applications.

Optimization of nutrient retention in whole flours extruded from cowpea biofortified grain

Whole flour of cowpea grains of the cultivar BRS Tumucumaque biofortified in iron and zinc were processed in a co-rotating twin-screw extruder Clextral HT 25. A central rotational composite design 23, combining temperature (from 86.4 to 153.6 °C), screw rotation speed (from 163.6 to 836.4 rpm) and moisture content (from 16.6% to 23.4%), was used to assess the effects on flour constituents. The three variables significantly affected (p < 0.05) the levels of protein and copper in the extrudates. The reactions of the extrusion process caused a decrease in the levels of proteins and an increase in the levels of copper, zinc and potassium, and these amounts were accentuated as the values of the process variables approached those of the central point region. Extreme conditions at high rotational screw speeds combined with low moisture content reduced the magnesium content, at the opposite end of the values for these two variables, the intensity of the reduction was lower. In the analysis of global desirability, it was found that the extrusion condition at 112.6 °C, 587.4 rpm and 23.4% moisture provided the highest nutrient retention. The levels of iron and zinc remained above 60 and 40 mg kg-1, respectively, in extruded products.

Vitamin D-enhanced pork meat consumers’ purchase intention: an exploratory case study in Spain

This paper investigated if Spanish consumers would be willing to consume vitamin D-enhanced pork meat from animals fed on mushrooms treated with ultraviolet (UV) light. The questionnaire briefly explained the context of the study (vitamin D deficiency) and asked the consumers to choose answers with which they were most in agreement (non-enriched meat, enriched meat with synthetic vitamin D or enriched meat with vitamin D from UV-irradiated mushrooms). A survey was conducted to 400 non-vegan nor vegetarian consumers in Aragón (Spain) by direct invitation. Sampling was carried out in a random and stratified manner, by province, gender and age group using the Aragón population data for 2017 (INE). Some sociodemographic, health and consumption habit data were requested. Most consumers preferred non-enriched meat. Treatment with UV-irradiated mushrooms was rejected by most consumers, and the consumers who presented any willingness to buy meat enriched with UV-irradiated mushrooms were in the youngest age group.

Texture profile of surimi-like material from mechanically deboned turkey meat

The study aimed to evaluate the textural properties of turkey surimi-like (TSL) gels from mechanically deboned turkey meat (MDTM) by washing procedures. The effects of water, sodium chloride, sodium bicarbonate, and potassium phosphate buffer washing solutions, cycles, and salt addition were investigated. Sodium bicarbonate washing solution produced lightened and whitened cooked gels. Addition of salt reduced (p < 0.05) cooking loss and increased (p < 0.05) hardness and chewiness. TSL gels from sodium bicarbonate had the lowest (p < 0.05) cooking loss and hardness, and increased (p < 0.05) adhesiveness after two washing cycles. Scanning electron micrographs showed fine-stranded gel structures formed at low ionic strength and coarsely aggregated gel structures at high ionic strength. Salt addition improved the TSL gelling properties. Two washing cycles of MDTM with sodium bicarbonate solution generate high-quality colorless gels of TSL with proper textural properties and could be suggested as an alternative meat source in the manufacturing of surimi-based foodstuffs.

Assessing the implementation of food defense requirements in industrial meat-based food processors

Food defense is the effort to protect food from causing harm to the consumer, including security procedures to mitigate intentional acts of adulteration. To assure entry in new markets, food companies need to develop and implement food defense strategies through third-party certification. Although there are some programs designed to assist food business operators in creating effective food defense strategies, this is still not regarded as a priority by food companies. As a first aim of this work, a first-party audit of two meat-producing industries was performed to verify the implementation of food defense requirements. The second purpose of the work was to compare vulnerabilities identified in those two food industries with the ones detected in other previously certified food units in Portugal. For such, a food defense requirements checklist was prepared for the audit and a private certification database was consulted to compare audit results with those from other food business operators certified by at least one international food defense standard. Audit results revealed that both industries were above 50% in overall compliance regarding food defense requirements; still the main vulnerabilities were related to the lack of a food defense plan, the failure to identify critical areas, ineffective warning systems and no training in food defense. Similar vulnerabilities were detected in other certified national food business operators, leading to the conclusion that implementation of food defense requirements seems to be underestimated. As an intervention strategy proposal, food defense training would be of upmost importance to get staff and managers acquainted with the concept.

Uma abordagem dos ensaios in vitro para estimar a absorção dos minerais em fórmulas infantis

Resumo A fórmula infantil é a opção de alimento mais recomendada quando a amamentação não é possível. Para o melhor entendimento do comportamento gastrointestinal e da absorção dos nutrientes presentes nas fórmulas infantis, realizam-se estudos que simulam os processos de digestão. Este trabalho teve como objetivo discutir a evolução das fórmulas infantis com foco na avaliação da absorção de Ca, Cu, Fe, K, Mg, Mn, P e Zn, identificando métodos disponíveis para a avaliação de bioacessibilidade e de biodisponibilidade, de forma a melhor entender a absorção desses nutrientes. Para isto, foi realizada uma revisão bibliográfica sobre fórmulas infantis e os métodos in vitro mais utilizados no estudo de minerais, com foco no consumo, na qualidade e nos aspectos tecnológicos. Foi constatada uma tendência mundial no aumento do consumo de fórmulas infantis e verificou-se que estudos de biodisponibilidade e bioacessibilidade de minerais, mesmo que ainda escassos, colaboram para a evolução e o desenvolvimento deste produto, visando a uma aproximação com a composição do leite materno. A pesquisa mostrou que a composição da fórmula infantil vem sendo constantemente aperfeiçoada por revisões das legislações e pela indústria, e que, para a obtenção de uma fórmula infantil com alta capacidade de absorção de nutrientes, devem ser realizados estudos de bioacessibilidade e/ou de biodisponibilidade, pois estes estudos possibilitam uma melhor compreensão da influência dos diferentes ingredientes na absorção dos nutrientes. Os estudos também mostraram que, para uma ingestão mais equilibrada, nas diferentes fases do lactente, são necessárias diferentes composições dos nutrientes nas fórmulas infantis.

Sensory analysis of curly kale produced under conventional and hydroponic systems

The consumption and cultivation of curly kale in Brazil is recent and information on production systems and their acceptance by the consumer are scarce. The aim of this work was to evaluate the sensory characteristics of curly kales cultivated using the conventional and hydroponic systems, considering the treatments: cultivation under the conventional system, without fertilization (A), conventional system with organic fertilizers (C, E) and hydroponic system (F). The harvests were performed at 60, 90 and 120 days after planting for the plants cultivated using the conventional system and at 30 days for the hydroponic system. The total chlorophyll index content and the sensory analyses of ranking of difference and acceptance were analyzed. The lowest chlorophyll index in the curly kales was verified for the one cultivated under the hydroponic system. In the ranking test, the darkest green color was obtained for the curly kale produced using the conventional system and for the attributes aroma, sweet and bitter taste and crunchiness, there was no significant difference.

Biospeckle Laser Technique for mechanical damage assessment in Tommy atkins mango fruits

The objective of this study was to evaluate the response of biological activity measured by the Biospeckle Laser technique applied to mangoes (Mangifera indica L.) subjected to mechanical damage at different stages of maturation. The tests were carried out twice a week for twenty-one days, and 40 mangoes of the variety Tommy Atkins were used. The procedure was divided into two stages: the first simulated the impact on fruits, and in the second stage, the laser light was applied to the impacted area. After laser application, the images of all fruits were submitted to graphic processing, in order to obtain maps of biological activity of the fruits. The Biospeckle laser technique associated with image analysis allowed the identification of distinct biological activity levels in the mangoes, certifying its potential application as a non-destructive test tool, in the monitoring of biological activity in fruit samples.

Caracterizações físico-química e sensorial de estruturados da polpa concentrada de jabuticaba

Resumo A jabuticaba é nativa da Mata Atlântica do Brasil, sendo uma das frutas mais cultivadas em pomares domésticos, podendo ser consumida in natura ou industrializada. Pela multiplicidade de usos, apresenta apreciável potencial econômico, mas não tem valor comercial alto por ser perecível. Estruturados da polpa concentrada de jabuticaba foram obtidos empregando-se hidrocoloides, como pectina e gelatina, além de edulcorantes, como maltose, sorbitol, glicose e glicerol, considerados supressores da atividade de água. A polpa de jabuticaba e os estruturados obtidos foram caracterizados quanto ao pH, à acidez titulável, à umidade, a sólidos solúveis totais, teor de cinzas, lipídeos, proteínas, açúcares redutores e não redutores e minerais (sódio e potássio). Quanto à análise sensorial foram realizados testes de aceitação e intenção de compra dos estruturados de jabuticaba, obtendo-se boa aceitação dos avaliadores, apresentando índices elevados de intenção de compra. As formulações F1 (contendo glicose, gelatina e pectina) e F4 (contendo sorbitol, gelatina, pectina e maltose) apresentaram diferenças nas proporções de açúcares utilizados, mostrando vantagem em relação às demais formulações, no que diz respeito ao custo para elaboração e ao menor teor de açúcar. Outra vantagem refere-se ao uso de sorbitol, que possui mais poder adoçante comparado à glicose, utilizado na F4, sendo uma alternativa viável para a substituição da glicose, tornando o estruturado mais saudável por conter menor teor de carboidrato. Assim, como as formulações F1 e F4 foram bem aceitas pelos avaliadores, poderiam ser as mais indicadas para a produção pelas indústrias de alimentos.

Effect of X-rays on structural, physicochemical and functional properties of gluten protein

The gluten protein was exposed to the X-ray radiations for different time range, comprising 1 and 3 seconds. The objective of this study was to determine the effect of x-ray radiations on the physicochemical properties of gluten protein. Different functional properties of proteins like water and oil holding capacities, protein solubility, emulsification activity, and stability index, foaming action and stability, water solubility, protein, and moisture content, along with SDS PAGE, FTIR, Xeta potential net charge was carried out to evaluate the effect of X-ray radiation on gluten protein. Results showed that the enhancement of water holding capacity up to 38.12%, as well as oil holding capacity up to 35% could be seen, whereas a significant decrease in emulsification activity and stability index, foaming capacity and stability, even protein content could be observed in treated samples. The net charge on protein in water solution was found to increase towards the positive side. The structure of the protein remained unchanged based on no change was observed in SDS PAGE electrograph, FTIR secondary structure region. Hence, X-ray treatment can be a possible way to alter the protein structure for “tailor-made applications” in food industries.