Effect of Fermentation Time and Leavening Agent on the Quality of Laboratory Produced and Market Samples of Masa (A Local Cereal Based Puff Batter)

Abstract

Evaluation of production techniques, quality of market samples and effects of fermentation times (6 and 8hrs), leavening agents (yeasts and baking powder) and shelf life (fresh and 24h) on the quality of masa were carried out through interviews, processing operations, laboratory analyses and sensory studies. Statistical analyses were carried out using the SPSS Statistical Package. Variations in processing techniques among masa producers were method of preparing the rice, soaking time for the rice (4 – 6h), the time paste was allowed to stay before baker’s yeast was added (3 – 4h), frying time (4 -5 minutes) and ratios of cooked rice to soaked rice (1: 2 and 1: 4). Uniform practices among masa producers were washing, wet-milling, fermentation time (overnight), addition of yeast, salts and sugars and dilution of fairly thick batter with trona (baking powder) before frying. Functional properties of rice were foam capacity (23.7%), foam stability (88.5%), water absorption capacity (0.02%), gelation capacity (20%), gelatinization temperature (82oC) and gelation time (20 minutes) Significant differences were observed between the masa samples for ash, moisture, protein, lipid and total bacterial counts (p ≤ 0.05). Their ranges for both laboratory-processed and market samples, respectively were; moisture (10.2 – 11.7% and 12.0 – 13.7%); protein (7.1 – 7.6% and 7.6 – 8.2%); lipid (1.9 – 2.4% and 2.4 – 2.6%); ash (0.4 – 0.7% and 0.6 – 0.8%) and total bacterial counts (1.2 x 101 – 1.6 x101 cfu/g). For the first day of their production, significant differences (p ≤ 0.05) were observed for all the sensory factors for both laboratory-processed and market samples of masa. Based on sensory scores, all the laboratory-produced masa samples were organoleptically acceptable without much significant difference (p ≥ 0.05) except for masa fermented for 8h without leavening agent. The mean sensory scores of all fresh market samples of masa were less than 4.0 on a 7-point Hedonic scale. Significant differences were observed between the market and laboratory processed samples of masa after the first day of production for all the sensory factors (P ≤ 0.05) and 50% of market and laboratory produced masa samples were not sensorially acceptable. Unlike freshly produced (for both market and laboratory) masa samples, it was found out that after the first day (24h) of production, the trend was not the same. This is because unlike market samples of masa, laboratory prepared masa samples without leavening agents, were as unacceptable as masa samples with leavening agents.

Key words: Masa, quality, Fermentation, Leavening, processing