ABSTRACT: The effect of ultrasound on Biceps femoris muscle tenderness was investigated using a 22 Central Composite Rotatable Design (CCRD) with triplicates at the central point. We evaluated the following independent variables: ultrasound intensity ranging from 11.30 to 33.90 W cm-2 and exposure time between 35 and 205 s. The ultrasound bath’s frequency (80 kHz) and temperature (10 ºC) were the fixed ones. To validate the model, the muscle was treated at the CCRD’s optimized condition (80 kHz, 22.60 W cm-2, 120 s, 10 ºC) evaluated, and compared with the muscle control sample (non-treated). A 22% shear force reduction was observed compared to the control sample (no ultrasound treatment) after 144 h, and stored at 5 ºC. Moreover, a sarcoplasmic calcium concentration increase was noted for ultrasound-treated muscle, probably activating the calpain enzyme system. In contrast, no significant influence (P > 0.05) was observed for pH, color index, lipid oxidation, water holding capacity, and drip loss by ultrasound treatment at the optimized conditions. Therefore, ultrasound application is promising and suitable for improving muscle tenderness without losing meat quality. This study highlighted the ultrasound effect on the tenderness of a less studied muscle (Biceps femoris) by combining short ultrasound exposure (120 s) and an 80 kHz frequency.

RESUMO: O efeito do ultrassom sob a maciez do músculo Biceps femoris foi avaliado usando um Delineamento Composto Central Rotacional (DCCR) 22 com triplicatas no ponto central. As variáveis independentes estudadas foram a intensidade do ultrassom que variou de 11,30 a 33,90 W cm-2 e o tempo de exposição de 35 e 205 s. A frequência do banho de ultrassom (80 kHz) e a temperatura (10 ºC) foram fixas. Para validar o modelo, a carne foi tratada na condição otimizada do DCCR (80 kHz, 22,60 W cm-2, 120 s, 10 ºC), avaliada e comparada à amostra controle (não tratada). Uma redução de 22% na força de cisalhamento foi observada em comparação à amostra controle após 144 h e armazenada a 5 ºC. Além disso, um aumento da concentração de cálcio sarcoplasmático foi observado para o músculo tratado com ultrassom, o que provavelmente ativou o sistema enzimático da calpaína. Em contraste, o tratamento com ultrassom nas condições otimizadas não influenciou significativamente (P > 0,05) o pH, cor, oxidação lipídica, capacidade de retenção de água e perda de gotejamento. Portanto, a aplicação do ultrassom é promissora e adequada para melhorar a maciez do músculo sem perder a qualidade da carne. Este estudo destacou o efeito do ultrassom na maciez de um músculo pouco estudado (Biceps femoris) ao combinar exposição curta ao ultrassom (120 s) e uma frequência de 80 kHz.

Coffee is one of the most popular beverages in the world, however, little information is found regarding the mineral composition of commercial roasted and ground coffees (RG) and its correlation with organic bioactive compounds. 21 commercial Brazilian RG coffee brands - 9 traditional (T) and 12 extra strong (ES) roasted ones - were analyzed for the Cu, Ca, Mn, Mg, K, Zn, and Fe minerals, caffeine, 5-caffeoylquinic acid (5-CQA) and melanoidins contents. For minerals determination by flame atomic absorption spectrometry (FAAS), the samples were decomposed by microwave-assisted wet digestion. Caffeine and 5-CQA were determined by liquid chromatography and melanoidins by molecular absorption spectrometry. The minerals and organic compounds contents association in RG coffee was observed by a principal component analysis. The thermostable compounds (minerals and caffeine) were related to dimension 1 and 2, while 5-CQA and melanoidins were related to dimension 3, allowing for the T coffees segmentation from ES ones.

Abstract Milk is a key food worldwide prone to mycotoxins contamination. Lactobacillus plantarum and prebiotics detoxification ability was evaluated by a Plackett-Burman Design considering the reduction of aflatoxin B1 (AFB1) and its bioaccessibility in artificially contaminated ultra-high temperature cow milk. Six variables were evaluated: AFB1 concentration (from 5.0 to 10.0 μg L−1); incubation time (0 to 6 h); and inulin, oligofructose, β-glucan, and polydextrose concentrations (from 0.00 to 0.75%). The reduction in AFB1 ranged from 0% to 55.85% and in vitro bioaccessibility from 15.62% to 51.09%. The greatest reduction in AFB1 occurred by adding L. plantarum combined with inulin, oligofructose and β-glucan. The greatest reduction in bioaccessibility occurred by adding inulin or oligofructose and L. plantarum with a 10.0 μg L−1 AFB1 concentration. A sharp reduction in AFB1 was accompanied by higher bioaccessibility rates, and in this case, bioaccessibility is considered the main factor to ensure a low AFB1 absorption by the body. The best experimental condition was 10.0 µg L-1 AFB1, added of L. plantarum and inulin or oligofructose (0.75%), ensuring > 16% final bioaccessibility. Such results represent a safe AFB1 decontamination level for milk.

Abstract The vinegar is a millenary food, appreciated by consumers worldwide. The rice bran is a rice-processing by-product produced in a large scale, mainly employed in feed. This study describes a method for defatted rice bran (DRB) vinegar production by submerged fermentation, with optimized aeration and stirring conditions, evaluating its physico-chemical properties and acceptance. A 22 Full Factorial Design (FFD) was applied to evaluate the aeration (0.25-1.00 VVM) and stirring (100-500 rpm) effect on the stoichiometric yield (SY), total concentration of ethanol and acetic acid yield (TCY), and acetic acid productivity (AAP). SY ranged from 26.26 to 79.97%, TCY ranged from 78.04 to 100.50%, and AAP varied from 0.056 to 0.473 g L-1 h-1. The stirring had a positive effect in the SY and TCY, while both aeration and stirring had a positive effect in the AAP (p ≤ 0.05). The FFD allowed an acetic acid increase of ≅ 750 times under aeration of 1.00 VVM and stirring of 500 rpm, which made it possible to develop an industrially compatible method for vinegar production using DRB as substrate. Furthermore, DRB presents potential for vinegar production, with functional characteristics - including antioxidant activity - and sensorially accepted.

Abstract The gluten is a protein associated with a numerous food allergy cases. As the gluten-related disorders relates is increasing, the demand for gluten-free breads (GFB) has been also increasing. The aim of this study was to obtain a GFB with increased nutritional aspects and sensorially accepted. A Central Composite Rotatable Design (CCRD) 23 was employed in order to choose the ideal proportions of partially defatted chia flour (PDCF) (1.23 to 24.77%), hydroxypropylmethylcellulose gum (HPMC) (0.00 to 2.51%), and Xanthan gum (XG) (0.00 to 2.51%) in a mixed flour used in GFB. The responses evaluated in GFB were: total lipids, protein, ash, carbohydrate, and omega-3 content, specific volume, L*, a*, and b*. The sensory acceptance was also evaluated. PDCF was the variable with higher effects in nutritional aspects; in high levels PDFC increase the protein, ash, and omega-3 content and decrease carbohydrate content of GFB. Although PDCF addition in the higher proportions negatively influenced the color parameters - decrease L* and increase a* - the mixed flour with 20% of PDCF, 0.51% of HMPC and 0.51% of XG added to GFB, was the most accepted for overall acceptance.

RESUMO: O farelo de arroz é um subproduto do processo de moagem do arroz, encontrado em abundância em todo o mundo e destacado devido ao seu teor de proteínas. Este estudo otimizou as condições para a extração assistida por ultrassom da proteína do farelo de arroz desengordurado (DRB) e caracterizou o concentrado de proteína do farelo de arroz (RBPC). Uma estratégia sequencial de desenho experimental foi empregada; o efeito do pH, temperatura, tempo de exposição ao ultrassom e amplitude foram avaliados em relação à porcentagem de extração proteica por um Delineamento Fatorial Completo (FFD) com frequências fixas (FFD -A: 37 kHz; FFD-B: 80 kHz). Posteriormente, a porcentagem de proteína extraída foi otimizada empregando um Planejamento Composto Central (variáveis: pH e tempo de exposição ao ultrassom) e o RBPC obtido foi caracterizado quanto às propriedades químicas e funcionais. O pH e o tempo de exposição ao ultrassom tiveram efeito positivo (P ≤ 0,05) na porcentagem de extração proteica. Além disso, a frequência de 37 kHz foi mais eficaz na extração de proteínas. A condição otimizada (frequência: 37 kHz; temperatura: 30 °C; pH: 10; tempo de exposição ao ultrassom: 30 min; e amplitude: 100%) permitiu 15,07% de recuperação de proteínas e o RBPC apresentou 84,76 g 100 g-1 de proteína. Magnésio e cobre foram os principais minerais da RBPC (34,4 e 25,5 µg g-1, respectivamente), enquanto a leucina foi o aminoácido limitante (0,42) e a treonina apresentou o maior escore químico (1,0). A solubilidade do RBPC foi mínima em pH 4 e superior em pH 6-10; a capacidade de absorção de água e óleo foi maior que a albumina sérica bovina (BSA) e a capacidade de emulsificação foi comparável à BSA, com uma estabilidade adequada. Assim, foi possível obter um RBPC com elevada pureza, maior do que o descrito na literatura, devido à otimização nas etapas do processo de extração, com propriedades funcionais adequadas para aplicação em produtos alimentícios, principalmente emulsificados.

ABSTRACT: Rice bran is a by-product of the rice milling process, found worldwide in abundance and highlighted due its protein content. This study optimized the conditions for ultrasonic-assisted extraction of protein from defatted rice bran (DRB) and characterized the rice bran protein concentrate (RBPC). A sequential strategy of experimental design was employed; the effect of pH, temperature, ultrasound exposure time, and amplitude were evaluated regarding the percentage of protein extraction by a Full factorial design (FFD) with a fixed frequencies (FFD-A: 37 kHz; FFD-B: 80 kHz). Subsequently, the percentage of protein extracted was optimized employing a Central composite rotatable design (variables: pH and ultrasound exposure time) and RBPC obtained was characterized regarding chemical and functional properties. The pH and ultrasound exposure time had positive effect (P ≤ 0.05) on percentage of protein extraction; moreover, 37 kHz frequency was more effective in protein extraction. The optimized condition (frequency: 37 kHz; temperature: 30 °C; pH: 10; ultrasound exposure time: 30 min; and amplitude: 100%) allowed 15.07% of protein recovery and the RBPC presented 84.76 g 100 g-1 of protein. Magnesium and copper were the main mineral in RBPC (34.4 and 25.5 µg g-1, respectively), while leucine was the limiting amino acid (0.42) and threonine presented the highest chemical score (1.0). The RBPC solubility was minimal at pH 4 and higher at pHs 6-10; the water and oil absorption capacity were higher than bovine serum albumin (BSA) and the emulsifying capacity was comparable to BSA, with a suitable stability. It was possible to obtain a higher purity RBPC than described in the literature, due to the optimization in the extraction process steps, with functional properties suitable for application in food products, especially emulsified ones.

Abstract The aim of this study was to evaluate the influence of chicken nuggets packaging attributes on Brazilian consumer purchase intention. Focus group technique was employed in order to identify the relevant packaging characteristics. Forty consumers were interviewed in six sessions where five different types of chicken nuggets packaging were evaluated. After identifying the most relevant parameters for the study (color, picture, brand, and price), the impact of each characteristic (factor) on the purchase intent was evaluated. The conjoint analysis technique was applied to 100 consumers data. Eight stimuli (labels) were prepared by combining two levels for each factor using a fractional factorial design 24-1. The price significantly influences at the time of purchase, which was quantitatively confirmed by the conjoint analysis, demonstrating the importance of a product supplied with a competitive market price. The picture influences at the time of purchase more than color and brand. Despite having less relative importance, warm colors and a brand already associated with the product might contribute positively to purchase intention.

The lactic acid bacteria are involved with food fermentation and in such cases with food spoilage. Considering the need to reduce the lactic acid bacteria growth in meat products, the aim of this work was to enumerated and investigated the lactic acid bacteria present on sliced vacuum-packed cooked ham stored at 4 °C and 8 °C for 45 days by phenotypic and molecular techniques. The quantification showed that the lactic acid bacteria were present from the first day with mean count of 1.98 log cfu/g for the four batches analyzed. The lactic acid bacteria grew rapidly on the samples, and plate counts around 7.59 log cfu/g and 8.25 log cfu/g were detected after 45 days of storage at 4 °C and 8 °C, respectively; storage temperatures studied showed significant influence on the microorganism in study growth. The predominant lactic acid bacteria associated with the spoilage samples at one day of storage includes Lactobacillus sp., the phenotypic overlap Leuconostoc/Weissella sp. and Enterococcus sp. At 45 days of storage at 4 and 8 °C the mainly specie was Lactobacillus curvatus, following by Lactobacillus sakei and Leuconostoc mesentereoides; the Enterococcus sp. was not present in the samples.

Mixed flavor beverages represent a trend that is gaining the allegiance of potential fruit juice consumers. The present study proposed to prepare mixed flavor beverages and verify their consumer acceptance. Cajá beverage (sample A) was used as the standard. The other beverages were prepared by mixing the cajá-flavored product with other flavors: strawberry (B), pineapple (C), jabuticaba (D), mango (E) and cashew (F). The consumer profiles in the two regions studied were similar. Overall beverages B, A and F were the most accepted, with scores of 7.7, 6.4 and 6.2, respectively. Internal Preference Mapping showed that most of the consumers were located near beverages A, B and F, confirming the acceptance results. The consumers indicated appearance and flavor as the most appreciated characteristics in beverages A, B and F. Beverages A, B and F presented higher total soluble solids contents and viscosities than the other beverages. Consumer segmentation did not depend on the different levels of familiarity with the cajá flavor. Thus the preparation of mixed flavor beverages of cajá-strawberry and cajá-cashew is an excellent proposal because it presents flavors with good potential for marketing in different regions of Brazil.