RESUMO
Plant extracts have the potential to be used as food additives; however, their use have been limited by causing undesirable changes in the sensory attributes of foods. We characterized the mango seed extract as a preserving agent for fresh-cut mangoes. We established the maximum concentration of extract that, while increasing the antioxidant activity, and limiting microbial contamination of the fruit, did not negatively affect fruit sensory acceptability. The extract contained 277.4 g gallic acid equivalent (GAE)/kg dw (dry weight) of polyphenols and 143.7 g quercetin equivalent (QE)/kg dw of flavonoids. Antioxidant capacity values were 2034.1 and 4205.7 µmol Trolox equivalent (TE)/g against 2,2-diphenyl-1-picryl-hydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radicals, respectively. Chromatographic analysis revealed the presence of gallic and chlorogenic acids. The extract (16 g/L) inhibited the growth of Escherichia coli, Salmonella Typhimurium, Staphylococcus aureus and Listeria monocytogenes. The highest concentration with sensory acceptability was 6.25 g/L. At such concentration, the extract preserved fresh-cut fruits, increasing polyphenols (0.427 g GAE/kg fw (fresh weight)), flavonoid content (0.234 g QE/kg fw) and antioxidant activity (DPPH = 2.814 and ABTS = 0.551 mol TE/kg fw). It also reduced inoculated bacteria (range: 5.50 × 10³ to 1.44 × 105 colony forming units (CFU)/g). These results showed the importance of considering consumer acceptability to determine the effective concentration of plant extracts as additives.
RESUMO
Objetivou-se avaliar o efeito dos danos mecânicos provocados por impacto, corte e abrasão sobre a qualidade de banana 'Prata Catarina', submetida ao armazenamento refrigerado (14°C ±1ºC e 84% ±5% de UR durante 21 dias). Os frutos foram provenientes de um pomar comercial, localizado no município de Limoeiro do Norte-CE. O experimento foi instalado em delineamento inteiramente ao acaso, no esquema de parcelas subdivididas no tempo, tendo-se, nas parcelas, as amostragens ao longo do tempo e, nas subparcelas, os quatro tratamentos: testemunha ou ausência de dano mecânico (T1), impacto (T2), abrasão (T3) e corte (T4), com quatro repetições de dois frutos cada. Os danos por impacto e abrasão foram os que proporcionaram maior velocidade de amadurecimento, sendo que o dano por impacto proporcionou maior atividade da enzima polifenoloxidase. As bananas 'Prata Catarina' que não sofreram danos podem ser comercializadas por até 21 dias de armazenamento (14°C ± 1ºC e 84% ±5% UR), sem perda da qualidade.(AU)
The aim of this study was to evaluate the effect of mechanical damages caused by impact, cut and abrasion on the quality of 'Prata Catarina' banana subjected to cold storage (14°C±1°C and 84%±5% RH for 21 days). The fruits were from a commercial orchard in the city of Limoeiro do Norte-CE. The experiment was conducted in a completely randomized design in split plot in time, taking up the samples in portions over time and in the subplots the four treatments: control or absence of mechanical damage (T1), impact (T2), abrasion (T3) and cut (T4), with 4 replicates of 2 fruits. Damages by impact and abrasion were the ones which provided the highest speed of ripening, and the damage caused by impact provided greater polyphenoloxidase enzyme activity. 'Prata Catarina' bananas that suffered no damage can be marketed until 21 days of storage (14°C±1°C and RH 84%±5%), without loss of quality.(AU)