Effects of Pretreatment and Frying Temperature on Oil Content, Acrylamide Formation, Color, Texture, and Sensory Acceptance of Kerupuk Sanjai Cassava Chips from Bukittinggi, West Sumatra

Abstract

Kerupuk sanjai is a thin cassava (Manihot esculenta Crantz) chip that is a traditional culinary specialty of Bukittinggi, West Sumatra, produced by deep-frying uniformly sliced cassava in palm oil at high temperatures. As a high-carbohydrate starch-based fried product, kerupuk sanjai is susceptible to two principal quality and safety concerns: excessive oil uptake and the formation of acrylamide  a probable human carcinogen (IARC Group 2A) generated via the Maillard reaction between asparagine and reducing sugars above 120°C. This study systematically evaluated the effects of four pretreatment strategies control (no pretreatment), blanching (85°C, 2 min), soaking in 3% NaCl solution (40°C, 20 min), and pre-drying (60°C oven, 45 min)  combined with two frying temperatures (150°C and 170°C) on oil content, color (L* and a*), acrylamide concentration, textural hardness, and sensory acceptability of kerupuk sanjai. A 4 × 2 factorial Completely Randomized Design with three replicates was employed. Results demonstrated that both pretreatment and frying temperature significantly affected all measured parameters (p < 0.001), with significant interactions for acrylamide (p < 0.05). Pre-drying yielded the lowest oil content (22.3 ± 0.5% at 170°C), while blanching produced the lowest acrylamide concentration (180 ± 12 µg/kg at 150°C) and best colorimetric attributes. Increasing frying temperature from 150°C to 170°C increased acrylamide by approximately 3.0–3.5-fold across all pretreatments. The a* colorimetric parameter (redness) exhibited a strong positive Pearson correlation with acrylamide content (r = 0.97, p < 0.001), validating it as a non-destructive process control indicator applicable at the artisan production level. Blanching combined with 150°C frying is recommended as the safest processing combination, while pre-drying combined with 170°C provides the optimal balance between oil reduction and consumer acceptability (overall sensory score 4.1/5.0).