RESUMO
The aim of this research was to develop and characterize an innovative nectar formulation of Physalis peruviana fruits from the Argentinean Northern Andean region with optimized proportions of pulp and sucrose that maximizes the antioxidant activity and with good sensorial acceptance, using the response surface methodology as optimization strategy. Physicochemical characteristics (total soluble solids, titratable acidity and pH), antioxidant activity (measured as the free radical scavenging activity against DPPH·) and sensorial attributes (color, acidity, sweetness, texture, aroma and overall acceptance) were evaluated in a series of nectar formulations. A significant correlation between overall acceptance and antioxidant activity contributed to achieve the objective outlined. The mathematical modelling defined a nectar with 65% fruit juice and pulp and 8% sucrose; this nectar presented absence of indicator microorganisms (aerobic mesophilic microorganisms, molds and yeasts, Salmonella spp., total coliforms, and Staphylococcus aureus coagulase positive) despite having no added preservatives. ß-carotene and vitamin C contents (1.13 ± 0.02 and 16.56 ± 0.52 mg/100 mL respectively) and antioxidant activity towards DPPH· (EC50: 2.43 ± 0.07 mg/mL), ABTS·+ (3.48 ± 0.07 µmol Trolox/mL) and FRAP (10.16 ± 0.10 µmol Trolox/mL), make this nectar a functional food with potential for the food industry.
RESUMO
Considerando las importantes cantidades de residuos de polipropileno y con el fin de conocer si objetos de este plástico pueden ser biodegradados, a qué velocidad y con qué mecanismo, se estudia la evolución de la pérdida de peso, durante 14 meses, de trozos de bandejas de polipropileno, enterradas en humus de lombricultura, a 25ºC y 40-50 porciento de humedad, analizándose, además, al final de los ensayos, los espectros infrarrojo de muestra y testigo. Se verificó la biodegradación del plástico estudiado por gravimentría y por espectrofotometría, y se encontró que la degradación ocurre por ruptura de las uniones del carbono metínico del polipropileno
