Process Optimization for a Novel Kefir Candy With High Probiotic Viability

Kefir, a beverage produced by the action of lactic acid bacteria (LAB), yeasts and acetic acid bacteria on milk, has a long tradition of offering health benefits. The objective of this research was to optimize the best formula for producing the kefir candy with maximum viabilities of LAB and yeasts using the response surface modeling and the sequential quadratic programming (SQP) method. In this study, milk was mixed with 5% kefir grains and incubated at 20C for 24 h. The samples were blended with lyoprotectants (galactose, skim milk powder [SMP] and sucrose), freeze‐dried and then mixed with sweeteners and compressed to form candies. The ratio of the lyoprotectants was determined using response surface modeling for constructing a response surface model and then using an SQP method to optimize the model. Optimization results indicated that kefir containing galactose, sucrose and SMP at 4.53, 7.0 and 5.03% (w/v), respectively, produced a chewable tablet with the highest viability of the microorganisms investigated. A relatively higher survival of microorganisms could be achieved by placing the kefir candy product in a glass bottle with deoxidant and desiccant at 4C. PRACTICAL APPLICATIONS A number of novel fermented dairy products have been developed and marketed under the concept of probiotic products, but few of these products were associated with confectionary goods. The kefir candy created in the present study with high viable cell counts (10 6 –10 7 cfu/g) after extended storage (up to 2 months) provides a flavorful option to offer the health benefits of probiotics. This study not only provides an opportunity to resolve the difficulty of kefir commercialization due to its post‐acidity and gas production but also increases the variety of dairy products in the market.