Optimizing thermal product processing in oat drink production

Abstract

Milk alternatives such as soy, almond, and oat drinks have become staples in supermarkets due to their health benefits, great taste and sustainability affects. An increasing number of breweries are entering oat drink production, as the manufacturing process closely resembles traditional brewing. This allows efficient repurposing of existing equipment such as mills, mash tuns, and storage tanks. For industrial-scale production, thermal preservation by direct heating is the preferred method to ensure microbiological stability while maintaining desirable sensory qualities and minimizing off-flavours. A key factor for cost-effective production is maximizing the operational time of the ultra-high temperature (UHT) process, minimizing interruptions for cleaning and sterilization. However, the formation of fouling layers in the high-temperature sections of the system – often within just a few hours – poses a significant limitation. The extent of fouling is strongly influenced by the upstream hydrolysis process. This study aimed to investigate the factors contributing to fouling to enable precise adjustments to equipment and process parameters, as well as to optimize cleaning procedures (CIP). Therefore, oat drink was produced in-house from oat flour via enzymatic hydrolysis and subsequently subjected to direct thermal treatment at both pilot and industrial scales. The results demonstrated a clear influence of the applied temperature profile on fouling behaviour. Sedimentation characteristics, colour development, and sensory attributes of the thermally treated oat drink were evaluated.