Formulation Optimization and Real-time Dehydration Endpoint Control in Making a Gracilaria lemaneiformis Snack

  Objective   Formulation optimization and determination of endpoint for the dehydration process in making a chewy, non-tacky, palatable snack item containing seaweeds, Gracilaria lemaneiformis, were conducted.

  Method   To remove fishy note, the seaweeds were firstly inoculated with Saccharomyces cerevisia JJ4 and Lactobacillus paracasei subsp. RP38 to produce a fermentation liquid as the intermediate raw material for the snack making. Product formula and hot-air drying conditions were optimized based on the sensory scores of the finished samples in an orthogonal design experimentation. To achieve desirable texture as judged by the panel, moisture content and product hardness were used to establish a mathematical model for endpoint determination on the drying process.

  Result   The undesirable odor of the seaweeds was largely ameliorated by the induced fermentation with the two microbial agents. In addition to the adhesion and gelling effect brought by the polysaccharides in G. lemaneiform, sucrose at 400 g·kg⁻¹, malic acid at 6 g·kg⁻¹, pectin at 1.4%, and carrageenan at 0.5% were incorporated to formulate the snack item. The mixed paste was dried by a 60 ℃ hot-air dehydration process that followed a mathematical model of y = −10.519x + 350.45 with R²= 0.9945 (where, y represents hardness index, and x product moisture content). Based on the sensory panel evaluation, the moisture content at 16.5%±0.3% as the dehydration endpoint would produce the optimal product hardness of 174–179 N·cm^-2.

  Conclusion   The experimental snack made of the fermented seaweed liquid, sugar, and gelling ingredients had highly desirable textural and flavor qualities as judged by the taste panel. A mathematical model for real-time endpoint control on the dehydration process was established for commercial production of the new product.