Organic brown sugar and jaboticaba pulp influence on water kefir fermentation

ABSTRACT Water kefir is considered to be a functional food with probiotic characteristics. It can be improved with addition of organic brown sugar and fruits native to Brazil, such as jaboticaba. The objective of this study was to evaluate the effects of brown sugar type: organic and conventional and the presence or absence of jaboticaba pulp in water kefir fermentation, based on the carbohydrate, organic acid, mineral composition and color profile. The fermentation process was carried out in two stages: with kefir grains, for 24 hours, at 25 °C and after filtration, maintained for 24 h at 25 °C in hermetic bottles, followed by a period of 8h refrigeration, and monitored every 8 h. Scanning electron microscopy of the kefir grains was performed after 24 h. The major changes in physicochemical patterns occurred up to 40 h. The final beverages presented acidic characteristics as a result of the production of lactic, acetic and succinic acids. The total sugar content had a reduction of around 50%. The sucrose content was reduced and the glucose and fructose increased. The use of organic sugar influenced the composition of the minerals. The characteristics related to color showed a tendency to increase over the evaluated times. It was concluded that it is possible to produce beverages fermented by water kefir grains, using organic or conventional brown sugar and jabuticaba pulp, being an alternative for the substitution of soft drinks, since it has no preservatives or food colorings, presents lower content of sugars and can be handcrafted. RESUMO O kefir de água é considerado um alimento funcional com características probióticas. Pode ser melhorado com adição de açúcar mascavo orgânico e frutas nativas do Brasil, como a jabuticaba. Objetivou-se avaliar os efeitos do tipo de açúcar mascavo: orgânico e convencional e da presença ou ausência de polpa de jabuticaba na fermentação de kefir de água, baseada no perfil de carboidratos, ácidos orgânicos, composição de minerais e cor. O processo fermentativo foi conduzido em duas etapas: com grãos de kefir, por 24 horas, a 25 °C e após filtragem, mantido por 24 h a 25 °C em garrafas herméticas, seguida de um período de 8h de refrigeração, e monitorado a cada 8 h. Foi realizada microscopia eletrônica de varredura dos grãos de kefir decorridas 24 h. As principais mudanças nos padrões físico-químicos ocorreram até 40h. As bebidas finais apresentaram característica ácida em decorrência da produção dos ácidos lático, acético