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The antioxidant and antibacterial activity and toxicity of natural products can change according to plant variety, as well as the part of the plant which is analyzed. In this study, peel, pulp and seed of four avocado varieties (Quintal, Fortuna, Margarida, and Hass) were analyzed for antioxidant and antibacterial properties and toxicity. There are few studies in the literature comparing these three first varieties. Antioxidant capacity was measured using the DPPH (2,2-diphenyl-1-picrylhydrazil), ABTS [2,2'-azino-bis- (3-ethylbenzothiazoline-6-sulfonic acid)], and FRAP (Ferric Reducing Ability Power) methods, along with the content of phenolic compounds and flavonoids. Principal component analysis was applied for antioxidant tests. Antibacterial activity against food pathogens was assessed by the minimum inhibitory concentration and minimum bactericidal concentration tests. Toxicity was evaluated against Artemia salina and also by hemolytic activity. The ethanolic extract of Quintal variety peel presented the greatest antioxidant and antibacterial activity. This same extract showed no toxicity in the preliminary tests, and shows great potential for food industry application as an additive.

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Tenderness is the most important organoleptic characteristic of meat, and various methods have been developed to improve it. The purpose of this experiment was to evaluate the effect of different conditioning treatments of broiler carcasses on pH, cooking losses, shear values, R-values, and sensory tenderness of breast meat. All measurements were collected for breast muscle as follows: after 24 h of carcass aging (T1); after 24 h of carcass aging with muscle tensioning (T2); after 24 h of carcass aging with muscle tensioning, followed by muscle collection and marination in CaCl2 (T3); after hot-boning 15 min following slaughter (T4); after hot-boning 15 min following slaughter and marination in CaCl2 (T5). pH values in meat treated with CaCl2 were significantly lower than those in untreated meat from the aged carcass group (T3) or the hot-boning group (T5). Breasts from carcasses aged for 24 h (T1, T2, and T3) showed lower cooking loss than breasts harvested immediately after slaughter (T4 and T5). CaCl2 marination produced meats with cooking losses significantly higher than those observed for untreated meats. Regardless of muscle tensioning or marination treatments, aging of the carcass for 24 h (T1, T2, and T3) produced meats with lower shear values than those from hot-boned carcasses (T4 and T5). Hot-boned breasts treated with CaCl2 (T5) were judged less tender by panelists than breasts aged under muscle tensioning (T2 and T3).

RESUMO.O presente trabalho teve como objetivo a avaliação da cinética de produção de enzimas celulases pelo fungo Aspergillus niger e da cinética de desativação das celulases. Foi utilizado bagaço de cana-de-açúcar pré-tratado como fonte de carbono na fermentação para a produção do complexo celulásico e também como substrato da hidrólise enzimática. A. niger foi cultivado em três bateladas, cada uma contendo 10, 50 e 100 g L -1de bagaço pré-tratado com NaOH 4% (m v -1 ). A cinética da produção das celulases foi obtida determinando-se a atividade enzimática das amostras coletadas ao longo do tempo. As variações do pH também foram determinadas. A deativação enzimática foi avaliada determinando-se periodicamente a atividade das amostras armazenadas nas condições de resfriamento (4°C) e de congelamento (-18ºC). Conclui-se que o A. niger produz celulases quando cultivado em meio de cultivo contendo bagaço de cana-de-açúcar pré-tratado e que o tempo ideal para coleta do caldo enzimático foi de aproximadamente sete dias, com produtividade máxima de 0,0013 U mL . O complexo celulásico não sofre desativação se armazenado à temperatura de -18°C por 43 dias, mas perde cerca de 40% da sua atividade após 48h se armazenado a 4°C.Palavras-chave: fermentação, enzimas, bagaço de cana-de-açúcar, hidrólise enzimática, lignocelulose.ABSTRACT. Cellulases production by Aspergillus niger and cellulase deactivation kinetic. This work aimed to evaluate the kinetic for the cellulase production by Aspergillus niger and the deactivation kinetic of the cellulase enzymes. Cellulase were produced in three different batches using NaOH 4% (w v . The kinetic of the cellulase production was accomplished by periodically determining the cellulasic activity of the fermentation broth using pre-treated bagasse as the hydrolysis substrate. Changes in the pH also were determined. The cellulase deactivation kinetic was accomplished by periodically determining the cellulasic activity of the fermentation broth samples stored at 4°C and at -18ºC. One may conclude that Aspergillus niger produces cellulases when grown on medium with pretreated sugarcane bagasse as carbon source. The ideal time to collect the enzymatic broth was about seven days with maximum yield of 0.0013 U mL . The cellulase complex does not suffer considerable deactivation when stored at -18°C (freezer) for 43 days, however, the activity drops by 40% within 48 hours when stored at 4°C (fridge).