ABSTRACT Edible coating are commonly used as they minimize post-harvest losses and extend the shelf life of fruits. Therefore, in this study, analyzed the effect of edible coatings containing gibberellic acid (GA3) on the shelf life of tomatoes (Solanum lycopersicum L.). Tomatoes were divided into six groups: Uncoated (CT); coating with 75 and 100 mg L-1 of GA3 solubilized in water without adding pectin (A75 and A100, respectively); coating with 75 and 100 mg L-1 of GA3 with added pectin (P75 and P100, respectively); coating pectin only (PEC). Pectin-based coatings (PEC, P75, and P100) were produced by solubilizing pectin (3%) in water, followed by adding different concentrations of GA3.Treatments A75 and A100 were prepared with distilled water and 75 and 100 mg L-1 GA3. Tomatoes (turning stage) were immersed in the solutions for 3 min, dried at room temperature, and stored at 12 °C (90% RH). The pH, titratable acidity, soluble solids, color and weight loss were analyzed every four days for 32 days, and the firmness of the tomatoes was analyzed every seven days for 35 days. Coatings with GA3 maintained firmness, delayed weight loss, and decreased acidity, pH, sugar content, and color changes. Pectin-based coatings (P75, P100) were the most effective in delaying weight loss. The application of GA3 associated with pectin-based coatings delayed the ripening process, maintained the quality, and prolonged the shelf life of fruits. As this is an inexpensive technique, it may be used commercially.

RESUMO Revestimentos comestíveis são comumente utilizados pois minimizam perdas pós-colheita e prolongam a vida útil dos frutos. Neste estudo, analisou-se o efeito de coberturas comestíveis contendo ácido giberélico (GA3) na vida útil de tomates (Solanum lycopersicum L.). Dividiu-se os tomates em seis grupos: Não revestidos (CT); revestimento com 75 e 100 mg L-1 de GA3 sem adição de pectina (A75 e A100); revestimento com 75 e 100 mg L-1 de GA3 com adição de pectina (P75 e P100); revestimento com pectina (PEC). Revestimentos à base de pectina (PEC, P75 e P100) foram produzidos solubilizando a pectina (3%) em água, seguida da adição das concentrações de GA3. Os tratamentos A75 e A100 foram preparados com água destilada e 75 e 100 mg L-1 de GA3. Os tomates (fase de viragem) foram imersos nas soluções durante 3 minutos, secos à temperatura ambiente e armazenados a 12 ° C (90% UR). O pH, acidez titulável, sólidos solúveis, cor e perda de massa foram analisados a cada quatro dias durante 32 dias, e a firmeza a cada sete dias durante 35 dias. As coberturas com GA3 mantiveram a firmeza, retardaram a perda de massa e diminuíram a acidez, pH, teor de açúcar e as alterações de cor. Revestimentos à base de pectina (P75, P100) foram os mais eficazes em retardar a perda de peso. A aplicação deste revestimento retardou o amadurecimento, manteve a qualidade e prolongou a vida útil dos frutos. É uma técnica economicamente viável, podendo ser utilizada comercialmente.

Abstract This paper evaluated the drying kinetics at different temperatures and the effect of the drying temperature on the physical-chemical properties and active compounds of the residue from the industrial processing of camu-camu. The drying temperatures of 40, 50, and 60 °C were evaluated. The residues dried at different temperatures were characterized in terms of their pH, water activity, anthocyanins, flavonoids, carotenoids, phenolic compounds and Fourier transform infrared spectroscopy. The parameters of the Page model showed the best adjustments to the experimental data. Drying affected the concentration of active compounds in the camu-camu residue. At 60 °C, the degradation of flavonoids, anthocyanins, and phenolic compounds was lower than in the dry residue, possibly because less time was required to achieve equilibrium in moisture content. Thus, in order to maintain higher concentrations of active compounds in the residue, drying at higher temperatures is recommended.

Abstract The objective of this study was to evaluate the behavior of active compounds concentration present in the industrial by-product of acerola during drying using convective dehydration at 40, 50 and 60 °C. For this, flavones and flavonols, total proanthocyanidins, vitamin C, total phenolic content and antioxidant capacity as function of drying time were determined. The drying data were adjusted using the models of Page, Lewis, Henderson & Pabis, Modified Page and Logarithmic. In relation to the applied models, Page model presented the best fit. Acerola by-products dried at 40 °C showed higher concentrations of active compounds and higher antioxidant capacity. Although the drying process provoked changes in concentration of the active compounds, in the studied temperature range, significant concentrations of those bioactive compounds were observed. Thus, acerola by-product may present potential for application in different foods.

Resumo Frutos de acerola e camu-camu possuem alto teor de vitamina C que, no entanto, pode ser oxidada, dependendo das formas de armazenamento e normalmente os frutos são pouco consumidos na sua forma in natura. Desta forma, o presente estudo teve como objetivo produzir pó de acerola e camu-camu por secagem em spray dryer para manter a estabilidade da vitamina C durante o armazenamento. Os pós de acerola e camu-camu foram caracterizados em relação às suas características fisicoquímicas, atividade antioxidante, concentração de vitamina C e estabilidade, em diferentes condições de armazenamento (30 °C e 40 °C, 75% de umidade relativa). Em geral, os pós foram considerados estáveis, com baixa atividade de água (< 0,40) e umidade (< 4,0 g / 100 g de pó), além de alta concentração de vitamina C (1593,2 e 6690,4 mg / 100 g de pó para acerola e camu-camu, respectivamente). Além disso, uma alta atividade antioxidante foi observada pelos ensaios ABTS●+, DPPH• e FRAP. Os pós armazenados em menor temperatura (30 °C) apresentaram maior estabilidade em relação à vitamina C. Assim, pode-se concluir que os pós de acerola e camu-camu produzidos pela secagem por spray dryer são fontes potenciais de vitamina C e compostos ativos, podendo ser utilizados para diferentes aplicações na indústria de alimentos.

Abstract Acerola and camu-camu fruits possess high vitamin C content. However, since these fruits are little consumed in their fresh form, it is important to consider that vitamin C can be oxidized depending on storage conditions. Thus, this study aimed to produce acerola and camu-camu powders by spray drying to maintain the stability of their vitamin C content during storage. Acerola and camu-camu powders were characterized in relation to their physicochemical characteristics, antioxidant activity, and vitamin C concentration and stability under different storage conditions (30 °C and 40 °C, 75% relative humidity). In general, the powders were proven to be stable, with low water activity (< 0.40) and humidity (< 4.0 g/100 g powder), as well as high vitamin C concentrations (1593.2 and 6690.4 mg/100 g of powder for acerola and camu-camu, respectively). Furthermore, we observed a high antioxidant activity by ABTS●+, DPPH• and FRAP assays. The powders stored at lower temperature (30 °C) showed higher vitamin C stability. In conclusion, acerola and camu-camu powders produced by spray drying are potential sources of vitamin C and active compounds and are therefore suitable for several food industry applications.

Resumo O objetivo deste trabalho foi avaliar a eficácia do acetato de etila como solvente na extração de óleo de semente de macaúba (OSM), utilizando extração assistida por ultrassom (EAU). Verificou-se que o aumento na remoção de OSM pode ser obtido com o uso de maiores quantidades de solventes, maior temperatura e tempo de extração. Com isso, obteve-se o rendimento máximo de óleo (40,61%) proporcionado pela EAU a 60 °C, 45 min, e utilizando a razão solvente para grão de 12 (mL g-1), o qual foi superior ao obtido por n -hexano, nas mesmas condições experimentais. A EAU foi favorável na extração de óleo (p < 0,05) e apresentou rendimento próximo ao relatado pela extração clássica; no entanto, na EAU, utiliza-se menor tempo de extração e volume de solvente. O ácido láurico corresponde a ~44% da composição do OSM. Os óleos apresentaram baixos teores de ácidos graxos livres (<0,80%) e os fitoesteróis, campesterol e β-sitosterol, foram identificados no OSM com maiores teores no óleo obtido pela EAU.

Abstract The objective of this work was to evaluate the efficacy of ethyl acetate as a solvent in the extraction of macauba kernel oil (MKO) using ultrasonic-assisted extraction (UAE). It was shown that more MKO oil could be extracted with the use of larger amounts of solvent, higher temperatures and longer extraction times. Thus the maximum oil yield (40.61%) was obtained by UAE at 60 °C for 45 min, using a solvent to kernel ratio of 12 (mL g-1), obtaining a higher yield than that obtained with n-hexane under the same experimental conditions. UAE was favorable for this oil extraction (p < 0.05), presenting a yield close to that reported for classical extraction but with a shorter extraction time and smaller solvent volume. Lauric acid corresponded to ~44% of the MKO composition. The oils presented low free fatty acid contents (<0.80% wt), and the phytosterols, campesterol and β-sitosterol, were identified in the MKO with higher levels in the oil obtained by UAE.