Formulation and shelf-life evaluation of avocado (Persea americana) pulp incorporated instant buttermilk beverage.

Abstract

Buttermilk is a fermented dairy product that contains probiotics and avocado is a nutrient-rich fruit. The focus of this study was to develop a buttermilk beverage blended with Avocado pulp to increase consumer acceptability. Different concentrations (T1 = 0%, T2 = 10 %, T3 = 15%, and T4 = 20% w/w) of Avocado pulp were extracted and added to a conventional recipe of buttermilk. Sensory attributes, and overall acceptability were measured separately using thirty (30) trained panelists with five (5) points hedonic scale and selected the best formula with higher consumer acceptance. Selected formula and control samples were analyzed for pH, titratable acidity, and color within four (4) days intervals, and microbial tests were analyzed within 7 days intervals of 14 days. Proximate analysis was done for moisture %, crude protein%, fat %, Energy %, Carbohydrate %, and ash% in selected formula. All the parametric and non-parametric data were analyzed using SAS, SPSS, and MS Excel at 0.05 significant levels. Avocado-incorporated buttermilk beverage (T4 =20%) acquired the highest sensory acceptance. The titratable acidity for the T4 formula increases during storage life from 0.12 ± 0.005 to 0.46 ± 0.005 and the pH value declined from 6.48 ± 0.01 to 5.45 ± 0.02. According to Sri Lankan standards, titratable acidity and pH value were within the acceptable limits for 14 days of storage period. Proximate analysis carried out according to the AOAC procedures revealed that the fat content was 1.00% ± 0.1, protein content 5.60% ± 0.1, Carbohydrate 8.60% ± 0.1 and ash content 0.38% ±0.03, and energy 65.8 kcal/100g ± 0.1 were in the acceptable limits. The coliform was 11.0 ± 0.5 in T4 beverage samples. It can be concluded that the incorporation of Treatment 4 = 20% of Avocado pulp maintained the best sensory attributes, and chemical and physiochemical parameters in fourteen (14) days of storage life without adding any chemical preservative.