A new nanobiotechnology material for yogurt samples: Characterized nanotubes- Streptococcus thermophilus and Lactobacillus delbrueckii bulgaricus

Abstract

Salep glucomannan and whey protein isolate-based Lactobacillus bulgaricus and Streptococcus thermophilus nanotubes were successfully fabricated (<100 nm). As seen from TEM images, geometric structures with 7.534 +/- 1.286 nm size indicated nanotubes. Mass loss (<10%) depending on the thermal decomposition of fabricated nanotubes started around 180 degrees C. The effectively fabricated nanotube samples were added to yogurt samples with four variances. In this respect, as the number of used nanotubes in yogurt samples was increased (2%), the decline in pH value was defined to be lower by 1.45% as compared to (non-nanotubes: control) samples by 3.34% on the 14th day (p < 0.05). The culture yogurt samples (B: 1% and C: 2%) maintained 1.5-2 log CFU/g Lactobacillus bulgaricus and Streptococcus thermophilus more bacterial viability compared with the non-nanotube samples besides the total bacteria count of all samples was found between 9.215 and 11.623 log CFU/g for 28 days. The yogurt samples treated with nanotubes and then stored at 4 degrees C for 28 days had a higher sensory preference. Furthermore, a rapid decline between the nanotube yogurt sample and the control sample was detected by 1.60% and 26.10% (p < 0.05). The nanotube formulation successfully obtained from Lactobacillus bulgaricus and Streptococcus thermophilus within salep glucomannan and whey protein isolate nanocarrier will play a guiding role for further dairy product treatments among scientists and food manufacturers. Also, this kind of study can get interested in EFSA and FDA related to food nanoscience applications.