ABSTRACT
Aims@#The aim of this study was to screen lactic acid bacteria (LAB) isolates from fermented Sumbawa mare‘s milk that meet the requirements as starter cultures, and to evaluate the effect of the selected starter culture in improving the organoleptic quality of mare‘s milk fermentation. @*Methodology and results@#The LAB isolates (13 isolates) derived from naturally fermented Sumbawa mare‘s milk were firstly screened for acidification activity. Afterwards, the selected isolates were evaluated for the starter culture criteria such as technological properties (proteolytic test, lipolytic test, and exopolysaccharide production), food safety test (hemolytic test and antibiotic sensitivity test), antimicrobial activity test. The selected culture (SC) together with yogurt starter cultures (YC) and combination between the selected isolate and a mixture of both (MC) were used to ferment fresh mare’s milk. Six LAB isolates (DB7, BC10, DC4, BC9, DC10, and BC7) were obtained from the acidification screening. Isolate BC10 was the most potential isolate as starter culture due to its ability in terms of acidification and proteolytic activity, lack of lipolytic activity, no indication of pathogenic potency, as well as able to inhibit the growth of Escherichia coli ATCC 25922. However, this isolate was resistant to antibiotics kanamycin, trimethoprim, and cinoxacin. The isolate BC10 presented 99.99% sequence similarity with respect to Lactobacillus plantarum.@*Conclusion, significance and impact of study@#The selected starter culture (isolate BC10) was able to improve the organoleptic quality of fermented mare‘s milk especially aroma compared to the other starter cultures. Therefore, L. plantarum BC10 is a potential isolate to be used as starter culture for mare’s milk fermentation.
ABSTRACT
O presente trabalho teve como objetivo fazer uma análise comparativa da qualidade de preparações extrativas obtidas de Passiflora alata Curtis, além de descrever esse processo. O extrato líquido foi obtido por refluxo utilizando água como solvente em proporção 1:10. A preparação líquida foi submetida à secagem em spray dryer utilizando aerosil® e fosfato de cálcio como adjuvantes tecnológicos. A eficiência de extração foi avaliada através da determinação do resíduo seco e do teor de flavonoides totais por técnica de espectrofotometria no UV. O extrato seco foi avaliado quanto à viabilidade tecnológica a partir da determinação das características de granulometria e da estabilidade em ambientes de umidade relativa controlada. O teor de flavonoides totais para o extrato seco apresentou redução quando comparado à solução extrativa, indicando possível influência do processo de secagem na composição do material. Os resultados de caracterização tecnológica demonstraram que o processo de secagem utilizado garante uma uniformidade de tamanho particular, embora seja observada uma tendência de higroscopicidade do material em ambientes de elevada umidade relativa. As técnicas empregadas se mostraram viáveis para uso em ensaios quali-quantitativos aplicados à determinação da qualidade dos extratos desenvolvidos.
This paper describes a process to prepare liquid and dried aqueous extracts from aerial parts of Passiflora alata Curtis (sweet passionfruit) and reports a comparative analysis of the extractive preparations obtained. The extractive solution was obtained by refluxing the plant material with water in the proportion 1:10 (w/v). The aqueous extract was dried in a spray-dryer, with Aerosil® and calcium phosphate as processing aids. The extraction efficiency was assessed by weighing the dry residue and assaying the total flavonoid content by UV spectrophotometry. The particle size and hygroscopicity of the spray-dried powder were determined in order to assess its technological viability. In the solid state, the total flavonoid content was reduced, relative to the aqueous extract, which indicates a possible influence of the drying process on its composition. The technological characterization demonstrated that this drying process leads to particle size uniformity, though a tendency to hygroscopicity can be observed under conditions of high relative humidity. The analytical techniques employed proved to be viable for qualitative and quantitative assays used for quality control of the extracts developed in this study.