Use of jabuticaba (Plinia cauliflora) skin in the processing of ice creams / Uso de piel de jabuticaba (Plinia cauliflora) en el procesamiento de helados

ABSTRACT The aim of this work was to process jabuticaba skin aqueous extract, varying the crushing and sieving time and to develop ice cream with different concentrations of jabuticaba skin extract, evaluate its physicochemical, microbiological and bioactive composition. Different extractive processes of jabuticaba skin were tested. Extract A was crushed for 25 seconds and sieved, extract B was crushed for 25 seconds without sieving, extract C was crushed for 45 seconds and sieved and extract D was crushed during 45 seconds not sifted. From the extract that presented the highest indices of bioactive compounds, formulations of ice cream with concentrations of 5, 10 and 15% were elaborated. Extract B showed the highest content of phenolic compounds (201.81 mg gallic acid. 100 g-1 skins), anthocyanins (60.32 mg cyanidin-3 glycoside.100 g-1 peels) and significant antioxidant activity (5047.72 g skins. g-1 DPPH) and was chosen to be added in the ice cream. The evaluated ice creams met the microbiological standards established by the Brazilian legislation. The use of progressive concentrations of jabuticaba skin extract in the elaboration of ice cream increased the rates of phenolic compounds and antioxidant capacity. The values found were significant and generated an alternative use for jabuticaba skin, which is normally discarded.

RESUMEN El objetivo de este trabajo fue elaborar extractos acuosos de piel de jabuticaba, variando el tiempo de trituración y cribado. Además de desarrollar helados con diferentes concentraciones de extracto de piel de jabuticaba, evaluando su composición físico-química, microbiológica y de compuestos bioactivos. Se analizaron diferentes procesos de elaboración de extractos de cáscara de jabuticaba, siendo denominados extracto A - triturado durante 25 segundos y tamizado, extracto B - triturado durante 25 segundos no tamizado, extracto C - triturado durante 45 segundos y tamizado y extracto D - triturado durante 45 segundos sin cribado. A partir del extracto que presentó los índices más elevados de compuestos bioactivos, se elaboraron formulaciones de helado con concentraciones de 5, 10 y 15%. El extracto B fue el que presentó mayor contenido de compuestos fenólicos (201,81 mg ácido gálico. 100 g-1 piel), antocianinas (60,32 mg cyanidina-3 glycosideo.100 g-1 piels) y significativa actividad antioxidante (5047,72 g piels. g-1DPPH) siendo el elegido para ser añadido en el helado. Los helados evaluados se encuentran dentro de los patrones microbiológicos estabelecidos por la legislación brasileña. La utilización de concentraciones progresivas de extracto de piel de jabuticaba en la elaboración de helado incrementó los índices de compuestos fenólicos y de capacidad antioxidante. Los valores encontrados son significativos y genera una alternativa en el aprovechamiento de la piel de jabuticaba, normalmente descartada.

Optimization of ultrasound-assisted extraction of grape-seed oil to enhance process yield and minimize free radical formation.

BACKGROUND: Grape seeds are a relatively abundant source of oil and bioactive compounds. To use this byproduct, the current work aimed to optimize the ultrasound-assisted extraction (UAE) of grape-seed oil to obtain greater process yield and minimize free radical formation in the oil. RESULTS: The optimal condition was 15 °C with an ultrasonic wave amplitude of 42 µm, leading to a process yield of 82.9% and content of free radicals of 14.7 × 1017 kg-1 and 3.4 × 1018 kg-1 for samples stored for 7 and 30 days, respectively. No significant differences in fatty acid composition and acidity and iodine values were observed between samples. The oil obtained by ultrasound had greater phenolic compound content and antioxidant activity by ferric reduction than the control sample (without ultrasound application). However, higher content of free radicals and peroxide value was observed. CONCLUSION: Sonication improved extraction yield when compared to the process without ultrasound application. Moreover, UAE favored the extraction of phenolic compounds. As it enhanced process yield with the minimum formation of free radicals, UAE is a promising oil-extraction technology. © 2018 Society of Chemical Industry.