Effects of Extraction Temperature on Taro (Colocasia Esculenta) Mucilage as a Mayonnaise Natural Fat Replacer

Soo, Wan Qi (2026) Effects of Extraction Temperature on Taro (Colocasia Esculenta) Mucilage as a Mayonnaise Natural Fat Replacer. Final Year Project (Bachelor), Tunku Abdul Rahman University of Management and Technology.

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Abstract

The high fat content of mayonnaise has led to increased demand for healthier, low-fat alternatives using natural hydrocolloids. This study investigated the influence of extraction methods on taro (Colocasia esculenta) mucilage and its efficacy as a fat replacer in mayonnaise. The objectives were to compare hot water extraction (HWE, 70°C) and cold water extraction (CWE, 4°C) on mucilage yield and physicochemical properties, and to evaluate their performance at 30% and 50% fat replacement levels. Methodology involved characterizing the mucilage for yield, purity, and emulsifying properties, followed by a 12-day storage study of the formulated mayonnaise at room temperature to monitor pH, color, viscosity, and oxidative stability including peroxide value and Rancimat induction time. HWE provided a slightly higher yield (2.54%) due to starch gelatinization, resulting in higher total hydrolysable carbohydrates (72.23%, expressed as starch equivalents) and comparatively lower mucilage purity. Conversely, CWE produced a more refined mucilage with superior emulsifying activity (17.75 m2/g). In mayonnaise applications, taro mucilage acted as a potent oxidative stabilizer, treated samples maintained peroxide values below 11 meq/kg, compared to nearly 20 meq/kg in the control, and extended induction times up to 34.82 hours. While the 50% replacement level offered the highest oxidative protection, it resulted in a significant loss of structural viscosity and internal friction. The 30% fat replacement using HWE mucilage (H30) was identified as the optimal formulation, balancing brightness, emulsion stability, and rheological consistency. In conclusion, taro mucilage is a viable natural fat replacer that enhances the shelf life and functional quality of mayonnaise. Future studies are proposed to incorporate ethanol precipitation to obtain higher mucilage purity and conduct sensory evaluation to ensure consumer acceptance regarding mouthfeel. This study provides a foundation for utilizing taro corm as a source of functional ingredients in high-fat food systems.