Preparation and Characterization of 3D Printed Objects Based on Different Kefir Gels

Abstract

In this study, kefir-containing healthy snacks were produced by using 3D food printing technique. Although kefir has many important health benefits, its consumption is quite low. It was thought that kefir-containing snacks in attractive shapes produced with a 3D food printer could increase the kefir consumption. For this purpose, disintegrated kefir gels prepared with starch, gelatin and alginate were used as inks. First, the minimum gelation concentration (C*) of each gelator was determined. Then, disintegrated gels with concentrations of C*, C*+1%, and C*+2% were prepared with each gelator and the effect of gelator concentration on printing quality was investigated for each gelator. Printing quality was associated with storage modulus, loss factor and flow behavior, and the minimum gelator concentration required for a suitable formulation for 3D printing (highest printability and dimensional stability) was determined as 5%, 6% and 3% for starch, gelatin and alginate, respectively. Lactobacillus spp. and Lactococcus spp. contents of the starch-based sample were found to be significantly lower than those of fresh kefir and gelatin and alginate-based samples. Sensory properties and consumer appreciation were lower for the gelatin-based sample. Due to the high printing quality (98% printability and 99% dimensional stability), high probiotic content (7.81 and 8.13 log cfu/ml Lactobacillus spp. and Lactococcus spp. content, respectively) and high consumer appreciation (4.71 out of 5 for general acceptance), alginate-based sample (containing 3% alginate) was chosen as the best sample. In conclusion, new, chewable, alive, alternative kefir products were successfully developed for consumers seeking new ways of kefir consumption.