Southern-style Pad Thai sauce: From traditional culinary treat to convenience food in retortable pouches

Pad Thai, a Thai dish of stir-fried rice noodles and other ingredients, is one of the culinary heritages of Thailand. In the southern region of Thailand, Pad Thai has different characteristics from other areas because coconut milk and curry paste are used to produce a thick sauce prior to cooking. To commercially distribute this uniquely local culinary treat in a convenient form all over Thailand and other export markets, a shelf-stable sauce using heat sterilization should be developed. Retort processing technology with retort pouches can be used for this purpose. However, phase separation and lipid oxidation can occur and subsequently reduce the overall quality of retorted southern-style Pad Thai sauce. The application of an appropriate stabilizer and antioxidant can be used to prevent such problems. Thus, the objective of this study was to investigate the effects of stabilizers and antioxidants on the stability of retorted southern-style Pad Thai sauce. Southern-style Pad Thai sauce was prepared according to the traditional recipe in the presence of different stabilizers (2.3% potato starch (PS) + 0.1% xanthan gum (XG), 0.5% soy lecithin (LT), and 4% whey protein isolate (WPI)) and antioxidants (500 mg/kg ascorbyl palmitate + 500 mg/kg α-tocopherol (As + Toc), 100 mg/kg ethylenediaminetetraacetic acid (EDTA), 200 mg/kg butylated hydroxytoluene (BHT), and As+Toc+EDTA+BHT (mixed antioxidants)). Samples were packed in retort pouches and processed in a retort at 121°C with an F(0) value of 3.57 min. Results showed that the retorted southern-style Pad Thai sauce can be stabilized by 2.3% PS plus 0.1% XG in combination with mixed antioxidants. PS and XG helped stabilize the sauce with a desirable viscosity, water holding capacity, and color without any creaming layer and negative effect on sensory properties. Mixed antioxidants improved the oxidative stability of the retorted sauce by retarding the changes in the peroxide value and color during retorting. Consequently, the processing of southern-style Pad Thai sauce in retortable pouches could increase the market demand for this traditional product due to its convenience and ready-to-use features.