Optimization and Characterisation of a 3-Blend Plant Milk Beverage

Abstract

Plant milk beverages have become a necessity as they serve as an alternative for people with lactose intolerance, cow milk allergy, vegetarians and people who want to avoid cholesterol. They have numerous health benefits but their consumption is limited by their poor sensory profiles. Soymilk is the most popular and most widely consumed plant milk beverage in the world. Using local ingredients for commercial production of plant milk in Ghana is advantageous as these raw materials are easily available and are affordable. Preliminary work used melon seeds, peanuts and coconut to formulate one, two and three blend plant milk beverages, but their sensory profiles suggested that they will be unappealing to consumers. The purpose of this work was to use a consumer led approach to optimize and characterize those plant milk beverages. A focus group discussion using target consumers was organized to confirm the selection of the three ingredients (melon seeds, peanuts and coconut) used for the initial plant milk beverages and to understand which sensory properties of plant milk are desirable to consumers. The plant milk beverages were optimized based on the outcome from the focus group discussions. After optimization, the 3-blend beverages were then characterized by sensory methods (consumer acceptability tests using Relative Preference Mapping (RPM) and the traditional 9-point hedonic scale in a Balanced Incomplete Block design (BIB) and physicochemical analysis (proximate composition, pH, titratable acidity, color, and viscosity). RPM was used to test liking for the optimized beverages as well as compare them to existing commercial dairy milk and plant milk beverages. Consumer test using BIB was used to understand the effect of the various ingredients on consumer acceptability. During the focus group discussions, only coconut met consumer expectations, peanuts was to be roasted instead of blanched and tiger nuts was recommended as a suitable ingredient to be added to the other ingredients. From the RPM, two of the 3-blend beverages containing peanuts, tiger nuts and coconuts milk had liking scores comparable to the dairy milk and commercial plant milk beverage. The results from the consumer test using BIB showed that peanuts and coconut milk were responsible for the acceptability of the blends. Melon seeds milk decreased liking and tiger nuts milk had a fairly neutral effect on liking. The protein content of the reformulated 3-blend beverages was in the range of 1.65±0.06%-3.51±0.02%, the fat content was from 4.09±0.05%-6.54±0.04%, the ash content was from 0.25±0.01%-0.51±0.07%, carbohydrates from 4.28±0.01%-7.26±0.01%, the L values were in the range of 75.91±0.13-85.54±0.50, the range for pH was 6.74±0.00-6.87±0.01 and that for titratable acidity was 0.83±0.01-2.05±0.00. The viscosity of the beverages was from 1163.55±7.42-1814.85±2.47 centipoise. Using consumer insight led to optimization of the plant milk beverages leading to acceptability comparable to an already accepted commercial plant beverage.