a Corresponding author: chanthimap@kmutnb.ac.th Feasibility Study of Aseptic Homogenization: Affecting Homogenization Steps on Quality of Sterilized Coconut Milk Chanthima Phungamngoen 1,a , Tippunsa Asawajinda 1 , Rujira Santad 1 , Wanticha Sawedboworn 1 1 King Mongkut’s University of Technology North Bangkok, 129 M. 21 Noenhom, Maung, Prachinburi, 25230 Thailand Abstract. Coconut milk is one of the most important protein-rich food sources available today. Separation of an emulsion into an aqueous phase and cream phase is commonly occurred and this leads an unacceptably physical defect of either fresh or processed coconut milk. Since homogenization steps are known to affect the stability of coconut milk. This work was aimed to study the effect of homogenization steps on quality of coconut milk. The samples were subject to high speed homogenization in the range of 5000-15000 rpm under sterilize temperatures at 120-140 °C for 15 min. The result showed that emulsion stability increase with increasing speed of homogenization. The lower fat particles were generated and easy to disperse in continuous phase lead to high stability. On the other hand, the stability of coconut milk decreased, fat globule increased, L value decreased and b value increased when the high sterilization temperature was applied. Homogenization after heating led to higher stability than homogenization before heating due to the reduced particle size of coconut milk after aggregation during sterilization process. The results implied that homogenization after sterilization process might play an important role on the quality of the sterilized coconut milk. 1 Introduction Coconut milk is a liquid produced by soaking the white inner flesh of the seed of the coconut in water and straining. Coconut milk is commonly used in South East Asian cuisine for its aromatic property in curry and other gravy. The major components of coconut milk are water and fat which fat globules disperse throughout the water phase [1]. Sterilized coconut milk required high temperature for long processing time because it is an emulsion and low acid food (pH7). Separation of an emulsion into an aqueous phase and cream phase is commonly occurred and this leads an unacceptably physical defect of either fresh or processed coconut milk [2]. Moreover, the protein denaturation occurred leading to curding in liquid system occured when temperature reaching to 80 °C [3] which can affect the stability of the milk. Previous research works have demonstrated that fat particle size, dispersion, homogenization and temperature had significant effects on a stability of coconut milk [2, 4, 5]. However, after heated coconut milk product with high temperature leads to much quality degradation, i.e., separation and brown color in product. In the sterilization process of coconut milk, there is no homogenization again therefore had the opportunity to make the product less stable. Since homogenization steps are known to affect the stability of coconut milk, it is interesting to study the effects of homogenization steps on the stability, fat particle size and color of sterilized coconut milk. In this study, attempt was made to feasibility study of aseptic homogenization. The opjective of this work was to study the effect of homogenization steps on somes quality of coconut milk. 2 Materials and Methods 2.1 Sample preparation Coconut milk without added water from a local market was used in the experiments. The initial fat content of coconut milk was determined using Rose–Gottlieb method [6]. The fresh coconut milk was diluted by distilled water to obtain the coconut milk with 20% w/v fat. Emulsifier stabilizer mixture of Montanox 60 (Adinop, Thailand) and CMC (Thai Food and Chemical, Thailand) with a ratio of 0.6:0.6 %w/v [3] were added while the samples were heated and stirred continuously until sample temperature reached 70 C. 2.2 Homogenization steps 2.3.1 Effect of homogenization speed and heating temperature Applied the single step of homogenization (Polytron, model PT-MR 3100, Germany) at speeds of 5,000, DOI: 10.1051/ 02010 (2016) I , matecconf/2016 MATEC Web of Conferences 62 620 CCFE 2016 2010 © The Authors, published by EDP Sciences. This is an open access article distributed under the terms of the Creative Commons Attribution License 4.0 (http://creativecommons.org/licenses/by/4.0/).