The Effect of Different Starter Cultures of Lactobacillus paracasei M104 and Pediococcus pentosaceus M103 on the Physicochemical and Microbial Qualities of Fermented Goat Milk

Widodo Widodo,Nurliyani Nurliyani,Ari Surya Sukarno,Aryo Pujo Sakti,Endang Wahyuni

doi:10.21776/ub.jitek.2019.014.02.1

Abstract

The utilization of starter cultures is vital for dairy fermentation industries. Lactobacillus paracasei M104 and Pediococcus pentosaceus M103 have been isolated from goat milk and were demonstrated to acidify goat milk during fermentation. This study was conducted to compare the physicochemical and microbial qualities of goat milk fermented using these starter cultures either as a single starter or combined in goat milk. The treatments were L. paracasei M104 (Lp) and P. pentosaceus M103 (Pp) as single starter culture fermentation and combined (Lp/Pp) fermentation at a ratio of 1:1 at 6% inoculation (v/v). For control treatment, goat milk was fermented using yogurt starter, i.e., a combination culture of Streptococcus thermophilus and L. bulgaricus (St/Lb) at a ratio of 1:1 at 6% (v/v). The fermentation was performed by incubating the inoculated goat milk at 37°C for 18 h. The pH and degree of acidity were measured every 2 h during the fermentation process, whereas the physicochemical (pH, degree of acidity, lactose, protein, and viscosity) and microbial (total lactic acid bacteria/LAB) qualities were measured after the fermentation process. Data analysis revealed that the different starter cultures had no significant effect (P > 0.05) on the pH and degree of acidity, lactose and protein content, viscosity, and total LAB content. The goat milk fermented in this study had an average pH of 4.41 ± 0.11 and a degree of acidity of 1.26 ± 0.05%, a lactose content of 5.47± 0.80%, a protein content of 6.69± 1.52%, a viscosity of 1217 ± 395 cP, and a total LAB content of 9.57 ± 1.49 log CFU/mL. In conclusion, goat milk fermented using both single and combined starter cultures of L. paracasei M104 and P. pentosaceus M103 exhibited similar physicochemical and microbial qualities and required longer fermentation time compared with the control.

Highlights

Goat milk is one of the alternative diets that has several advantages compared with cow milk
Lactose is metabolized by bacteria through processes catalyzed by enzymes into glucose and galactose, which are metabolized through glycolysis into organic acids in the form of lactic acid or acetic acid (Walstra et al, 1999)
This study was conducted to compare the acidifying capabilities between combined L. paracasei M104 and P. pentosaceus M103 cultures and single culture fermentation and to evaluate the physicochemical and microbial qualities of the produced fermented milk

Summary

INTRODUCTION

Goat milk is one of the alternative diets that has several advantages compared with cow milk. The ability of lactic acid bacteria (LAB) to produce bacteriocin is known to contribute to the prolongation of the shelf life of fermented milk LAB comprise a group of bacteria that are commonly used as a starter culture in fermented milk products. These bacteria have fulfilled the food safety criteria and are generally considered as safe for consumption. Widodo et al (2016) isolated Lactobacillus paracasei M104 and Pediococcus pentosaceus M103 from Etawah crossbred (PE) goat milk. Both bacteria have been evaluated as starter cultures and have demonstrated the ability to acidify the media during fermentation (Widodo et al, 2016). This study was conducted to compare the acidifying capabilities between combined L. paracasei M104 and P. pentosaceus M103 cultures and single culture fermentation and to evaluate the physicochemical and microbial qualities of the produced fermented milk

MATERIALS AND METHODS

AND DISCUSSION

CONCLUSIONS