Karakteristik Bubuk Kakao Non Fermentasi pada Berbagai Konsentrasi K2CO3 dan Waktu Alkalisasi Menggunakan Microwave

Abstract

The demand for cocoa-based products with improved solubility and reduced bitterness has encouraged the development of processing methods for non-fermented cocoa powder, which naturally contains high polyphenol levels that cause bitterness and poor dispersibility in water. This study aimed to: (1) evaluate the effects of various K₂CO₃ concentrations and microwave alkalization times on the characteristics of non-fermented cocoa powder; (2) characterize its physical, chemical, and sensory properties; (3) determine the selected formula using the De Garmo effectiveness index; and (4) identify the optimal treatment combination. A two-factor Completely Randomized Design (CRD) was employed: factor K (K₂CO₃ concentration: K1=1%, K2=2%, K3=3% b/v) and factor W (microwave alkalization time: W1=4 min, W2=8 min, W3=12 min), with three replications, yielding nine treatment combinations. Non-fermented cocoa powder was mixed with K₂CO₃ solution at a 3:1 (v/b) ratio, alkalized in a 900 W microwave for the respective durations, cut, dried in a cabinet dryer at 65°C for 16 hours, ground, and sieved through 80 mesh. Hedonic tests assessed color, aroma, taste, and overall acceptance. The selected formula was further analyzed for physical quality (solubility, wetting time, sedimentation index, and color) and chemical quality (pH and total polyphenols via Folin-Ciocalteu method). Results showed that K₂CO₃ concentration significantly affected solubility, color (L*), pH, polyphenols, and sedimentation index (p<0.05), while the K×W interaction significantly affected solubility and wetting time. Higher K₂CO₃ concentrations increased solubility (up to 13.01%), raised pH, darkened the color, and reduced polyphenol content. Formula K2W2 (2% K₂CO₃ for 8 minutes) was selected with the highest effectiveness index of 0.63. This formula exhibited solubility of 10.54%, pH of 8.78, darker color (L* ≈ 42.7), lower polyphenol content, and higher sensory acceptance scores compared to the untreated control. However, particle size distribution and further improvement in wetting time may require additional optimization for commercial instant applications.