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.

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 A factorial categorical design totalling six treatments was applied to investigate the influence of the substitution of corn starch with whole and partially defatted chia flour under the technical characteristics (centesimal composition, instrumental analyses, and sensory evaluation) and nutritional disorders (composition of fatty acids and index of the nutritional quality of the lipid fraction) of ‘dulce de leche’ concentrated to 72 and 78 °B. The treatments with chia flour concentrated to 72 °B showed higher moisture content and lower compression force, and when the concentration range increased to 78 °B, the levels of total lipids amounted up to 1.40 times when compared to treatment with corn starch. The polyunsaturated fatty acids, particularly omega-3 and omega-6 levels, were higher in treatments with chia flour on both tracks of concentration, allowing a reduction in the atherogenic index and thrombogenic index effects and the n-6/n-3 ratio. The treatments of ‘dulce de leche’ with a lower concentration of soluble solids obtained greater acceptance and consumer purchase intention. The application of whole chia flour in small proportions and in the concentration of 72 °B was the most appropriate under the studied conditions, showing improvement in the nutritional quality and with good technical aspects of candy made with goat milk.

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.

As enzimas amiloglicosidase (AMG) e exo-poligalacturonase (exo-PG) foram produzidas simultaneamente por duas cepas de Aspergillus niger, através de fermentação em estado sólido usando farelo de arroz desengordurado como substrato. Foram avaliados os efeitos da cepa de Aspergillus niger, tipo de inóculo e adição de indutores no meio de cultura, utilizando-se um planejamento experimental fracionário 3² x 2¹. O máximo rendimento obtido foi 1310 U/g ms para a produção de AMG e 50,2 U/g ms para a exo-PG. Comparando-se estes resultados com dados da literatura pode-se dizer que os rendimentos obtidos foram aceitáveis e indicam que o farelo de arroz desengordurado é uma boa fonte de nutrientes. A produção de AMG e exo-PG foi significativamente afetada pelas variáveis cepa de A. niger e tipo de inóculo, enquanto a variável indutor não apresentou influência significativa na produção destas enzimas.

Amyloglucosidase (AMG) and exo-polygalacturonase (exo-PG) were simultaneously produced by two different strains of Aspergillus niger in solid-state fermentation (SSF) using defatted rice-bran as substrate. The effect of Aspergillus niger strain (t0005/007-2 and/or CCT 3312), inoculum type (spore suspension or fermented bran) and addition of inducers (pectin and/or starch) to the culture media was studied using a 3² x 2¹ factorial experimental design. The production of AMG and exo-PG was significantly affected by fungal strain and inoculum type but inducers had no effect. The maximum yields obtained were 1310 U/g dm for AMG using a spore suspension of A. niger CCT 3312 and 50.2 U/g dm for exo-PG production, using A. niger t0005/007-2 and fermented bran as inoculum. The yields obtained represented acceptable values in comparison with data available in the literature and indicated that defatted rice-bran was a good nutrient source.