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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.

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.

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The influence of different concentrations of NaCl (2.5% and 1.75%), basic electrolyzed water (BEW), and ultrasound (US, 25 kHz, 159 W) on the quality of fresh sausages was studied. During storage at 5 °C, TBARS, pH, Eh, aw, nitrous pigments, and bacterial evolution were evaluated at three specific time intervals: 1d, 15d, and 30d. At the same time, the volatile compounds and sensory profile were specifically assessed on both the 1d and 30d. Notably, sausages with 1.75% NaCl and BEW displayed higher pH values (up to 6.30) and nitrous pigment formation, alongside reduced Eh (as low as 40.55 mV) and TBARS values (ranging from 0.016 to 0.134 mg MDA/kg sample), compared to the 2.5% NaCl variants. Protein content ranged between 13.01% and 13.75%, while lipid content was between 18.23% and 18.86%, consistent across all treatments. Psychrotrophic lactic bacteria showed a significant increase in low-NaCl sausages, ranging from 5.77 to 7.59 log CFU/g, indicative of potential preservative benefits. The sensory analysis favored the TUSBEW70 treatment for its salty flavor on the 30th day, reflecting a positive sensory acceptance. The study highlights that employing US and BEW in sausage preparation with reduced NaCl content (1.75%) maintains quality comparable to higher salt (2.5%) counterparts. These findings are crucial for meat processing, presenting a viable approach to producing healthier sausages with reduced sodium content without compromising quality, aligning with consumer health preferences and industry standards.

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This study investigated the effect of a 50% reduction in sodium nitrite and the addition of nisin (200 mg/kg) and different concentrations (0, 0.5%, 0.75%, and 1%) of jabuticaba peel extract (JPE) on the main attributes affected by this chemical additive in Bologna-type sausages. The modified treatments showed approximately 50% lower residual nitrite than the control throughout the storage (60 days at 4 °C). The proposed reformulation did not affect the color (L*, a*, and b*), and the ΔE values (< 2) demonstrated high color stability during storage. Physicochemical (TBARS and volatile compounds) and sensory analyses performed to evaluate oxidative stability indicated that JPE exhibited antioxidant activity comparable to sodium nitrite. The microbiological quality of the reformulated products was similar to the control, but further studies should be conducted to assess the effect of this reformulation strategy on the growth of pathogenic microorganisms impacted by nitrite.

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The effects of ultrasound (US) on myoglobin modification, nitrous pigment formation, color, and total and free sulfhydryl content in nitrite-free pork meat batter were assessed. Five treatments were elaborated: Control (without US); TUS10'12 and TUS20'12 (sonication at 25 kHz, at 12 °C for 10 and 20 min, respectively); TUS10'18 and TUS20'18 (sonication at 25 kHz, at 18 °C for 10 and 20 min, respectively). Sonication for 20 min at 12 °C increased OxyMb and DeoxyMb pigments while reducing MetMb levels. This US condition also yielded higher red color indices and lower yellow color indices. Moreover, TUS20'12 exhibited enhanced nitrous pigment formation and decreased FerrylMb and free sulfhydryl (SH) values, indicating reduced oxidation in OxyMb and DeoxyMb pigments. In conclusion, the findings demonstrate that US can impart a cured color to nitrite-free meat products.

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Hydrogelled emulsions (HEs) of linseed oil and pea protein (PP) were produced with four levels (0, 5, 7.5, and 10%) of raspberry extract obtained by a green extraction technique (microwave hydrodiffusion and gravity-MHG). HEs were applied in burgers to replace 50% of pork backfat content. The products' technological, nutritional, oxidative, microbiological, and sensory properties were evaluated. Besides reducing the fat level by approximately 43%, the reformulation reduced the n-6/n-3 PUFA ratio to healthy levels, decreased the diameter reduction by 30%, and increased the cooking yield by 11%. Including 7.5 and 10% of raspberry extract in the HEs decreased the oxidative defects caused by the enrichment of the burgers with omega-3 fatty acids. In addition, the raspberry extract did not cause alterations in the mesophilic aerobic count and the burgers' sensory profile.

RESUMO

ABSTRACT: The determination of eugenol in clove essential oil was performed using a smartphone-operated device, which was used for image capture and processing. The colorimetric reaction with the Folin-Ciocalteu reagent was used, and the lighting conditions were evaluated to capture images directly in 2 mL disposable vessels. The free application PhotoMetrix UVC was used for partial least squares regression calibration with suitable values (R² greater than 0.99). The accuracy of the proposed method was compared with traditional methods, such as gas chromatography (GC) and spectrophotometry, and it can be observed that there were no significant differences (Student's t-test (P > 0.05), with agreements from 97% to 101%. The smartphone method allowed the evaluation of several samples in a few minutes, with simple analysis steps and easy interpretation of the results. The miniaturized scale allowed the use of small amounts of reagents with minimal waste generation. Therefore, the proposed method can be easily operated in the field and allows the evaluation of the quality of clove essential oil in places of restricted access without the need for a laboratory structure and specialized analysts.

RESUMO: A determinação de eugenol em óleo essencial de cravo-da-índia foi realizada utilizando um dispositivo operado com smartphone para captura e processamento de imagens. Para tal desenvolvimento foi utilizada a reação colorimétrica com o reagente de Folin-Ciocalteu. Foram avaliadas diferentes condições de iluminação para a captura das imagens diretamente em frascos descartáveis de 2 mL. O aplicativo livre PhotoMetrix UVC foi usado para a calibração por regressão de mínimos quadrados parciais com valores adequados (R2 maior que 0.99). A exatidão do método proposto foi comparada com métodos tradicionais, tais como cromatografia gasosa (CG) e espectrofotometria, sem diferenças significativas (teste t de Student (P > 0,05) e com concordâncias entre 97% e 101%. O método com smartphone permitiu a avaliação de várias amostras em poucos minutos, com etapas de análise simples e com fácil interpretação dos resultados. A escala miniaturizada permitiu o uso de pequenas quantidades de reagentes e mínima geração de resíduos. Portanto, o método proposto pode ser facilmente operado em campo e permite avaliar a qualidade de óleo essencial de cravo- da- índia em locais de acesso restrito, sem a necessidade de estrutura laboratorial e analistas especializados.

RESUMO

The determination of eugenol in clove essential oil was performed using a smartphone-operated device, which was used for image capture and processing. The colorimetric reaction with the Folin-Ciocalteu reagent was used, and the lighting conditions were evaluated to capture images directly in 2 mL disposable vessels. The free application PhotoMetrix UVC was used for partial least squares regression calibration with suitable values (R² greater than 0.99). The accuracy of the proposed method was compared with traditional methods, such as gas chromatography (GC) and spectrophotometry, and it can be observed that there were no significant differences (Student's t-test (P > 0.05), with agreements from 97% to 101%. The smartphone method allowed the evaluation of several samples in a few minutes, with simple analysis steps and easy interpretation of the results. The miniaturized scale allowed the use of small amounts of reagents with minimal waste generation. Therefore, the proposed method can be easily operated in the field and allows the evaluation of the quality of clove essential oil in places of restricted access without the need for a laboratory structure and specialized analysts.

A determinação de eugenol em óleo essencial de cravo-da-índia foi realizada utilizando um dispositivo operado com smartphone para captura e processamento de imagens. Para tal desenvolvimento foi utilizada a reação colorimétrica com o reagente de Folin-Ciocalteu. Foram avaliadas diferentes condições de iluminação para a captura das imagens diretamente em frascos descartáveis de 2 mL. O aplicativo livre PhotoMetrix UVC foi usado para a calibração por regressão de mínimos quadrados parciais com valores adequados (R2 maior que 0.99). A exatidão do método proposto foi comparada com métodos tradicionais, tais como cromatografia gasosa (CG) e espectrofotometria, sem diferenças significativas (teste t de Student (P > 0,05) e com concordâncias entre 97% e 101%. O método com smartphone permitiu a avaliação de várias amostras em poucos minutos, com etapas de análise simples e com fácil interpretação dos resultados. A escala miniaturizada permitiu o uso de pequenas quantidades de reagentes e mínima geração de resíduos. Portanto, o método proposto pode ser facilmente operado em campo e permite avaliar a qualidade de óleo essencial de cravo- da- índia em locais de acesso restrito, sem a necessidade de estrutura laboratorial e analistas especializados.

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This study was conducted to evaluate the effects of slaughtering feedlot Texel lambs during different climatic conditions on carcass and meat quality traits. Twenty castrated male Texel lambs (21.8 ± 0.62 kg) were distributed to two treatments according to the climatic conditions during the finishing period and at pre-slaughter: warm season (WS; mean temperature of 23.4 °C and 77.5% relative humidity) and cool season (CS; mean temperature of 14.9 °C and 79.5% relative humidity). During the pre-slaughter, thermal comfort was evaluated through the variables: respiratory frequency, rectal temperature, temperature of the ocular region, and temperature-humidity index (THI). After the finishing period, lambs were slaughtered, and carcass and meat quality traits were assessed. The THI values indicate that animals harvested in the WS spent 13 h of the day under potential thermal discomfort conditions in the week before slaughter and in the pre-slaughter period, whereas lambs harvested in the CS did not experience any thermal discomfort. Slaughter weight, carcass weight, carcass dressing, and backfat thickness were greater (P ≤ 0.03), whereas cooling losses were lower (P < 0.01) for lambs slaughtered in the CS. Moreover, thawing losses were lower (P < 0.01), whereas cooking losses were greater (P < 0.01) for lambs harvested in the CS. Lambs slaughtered in the CS also showed greater meat redness, yellowness, and chroma values (P < 0.05). Although carcass traits were affected by the greater thermal discomfort exposure, meat quality of lambs was less impacted by the climatic conditions at slaughter.

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Microalgae are photosynthetic microorganisms that stand out from conventional food sources and ingredients due to their high growth rate and adaptability. In addition to being highly sustainable, significant concentrations of proteins, lipids, and pigments accumulate in their cell structures from photosynthesis. Hence, this study sought to evaluate the food potential of Scenedesmus obliquus biomasses obtained from photosynthetic cultures enriched with 3, 5, 10, 15, 20, and 25% carbon dioxide (CO2) (v/v). Cultivations with 3, 5, and 10% CO2 showed greater amino acids and proteins synthesis; the protein content reached values above 56% of the dry biomass and high protein quality, due to the presence of most essential amino acids at recommended levels for the human diet. The highest concentrations of chlorophylls were found in cultures with 15, 20, and 25% CO2 (24.2, 23.1 and 30.8 mg g-1, respectively), although the profiles showed higher percentages of degradation compounds. Carotenoid concentrations were three times higher in cultures with 3, 5, and 10% CO2 (25.3, 22.7 and 18.1 mg g-1, respectively) and all-trans-ß-carotene was the major compound. Lipid synthesis was intensified at higher CO2 enrichment; the percentages obtained were 14.8% of lipids in the culture with 15% CO2, 15.0% with 20% CO2, and 13.7% with 25% CO2. In addition, greater polyunsaturated fatty acids accumulation and a significant reduction in the n6/n3 ratio were also observed at the highest CO2 concentrations. Our findings showed that CO2 treatments significantly altered all compounds concentrations in S. obliquus biomasses, which presented satisfactory composition for application in foods and as ingredients.

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A wide variety of by-products are produced by the industry when animals are slaughtered. However, the proteins present in these by-products, are not being fully useable, in the elaboration of value-added products. Staphylococcus xylosus is commonly used as a starter culture in meat products subjected to ripening for a long period, as it produces proteolytic and lipolytic enzymes that improve the sensory quality of the products. Ultrasound (US) has been arousing interest in the meat industry, as it reduces processing time and also improves the technological and sensory quality of meat products. However, the stimulate effect of US on the growth of S. xylosus in by-products from the poultry industry is still unknown. Thus, this study aimed to evaluate the stimulate effect of US on the growth of S. xylosus inoculated in by-products from the poultry industry. S. xylosus was inoculated (5.63 log CFU/g) in sterilized by-products from the poultry, which were then sonicated at 37 °C for 0, 15, 30, and 45 min according to the following parameters: frequencies of 130 and 35 kHz, amplitudes of 50% and 80% and normal and degas operating modes. The sonicated samples were incubated at 37 °C for 0, 24, 48, and 72 h. Soon after sonication, no stimulate effect of US was observed on the growth of S. xylosus. However, after 24 h of incubation, the samples sonicated for 15 and 30 min in normal mode, at 35 and 130 kHz, and amplitudes of 50 and 80% exhibited better stimulate effect at the growth S. xylosus counts (p < 0.01) when compared to the Control, with values of 8.23 and 7.77 log CFU/g, respectively. These results can be exploited to obtain new added-value products, having as raw material by-products from the poultry industry.