Improving the Viability of Probiotic Bacteria in Yoghurt by Homogenization

Abstract

In this study, the effect of homogenization pressures (100, 150 and 200 bar) at 50, 60 and 70C and stages (1 and 2) on viability of probiotic bacteria was investigated. The milk used for producing yoghurt samples was homogenized at 100, 150 and 200 bar at 50, 60 and 70C, then heated at 85C for 30 min. After cooling milk to fermentation temperature (42C), it was inoculated with mixture starter culture ABY-1 and incubated. During fermentation, pH dropped until it reached 4.5. After fermentation, yoghurt samples were held in refrigerator. Viability of Lactobacillus acidophilus and Bifidobacterium lactis was determined during a 21-day cold storage (4C). The results of this study showed that with increasing pressure, temperature and stages of homogenization, viability of probiotic bacteria increased during storage (P < 0.05). PRACTICAL APPLICATIONSThe viability of probiotic bacteria in probiotic products is so important; and nowadays, it is also considered by consumers. Probiotic yoghurt is one of the most widely used probiotic dairy products around the world, and therefore finding an efficient and practical way to produce it with the highest viability of the probiotic bacteria seems necessary. Homogenization is one of the most important steps in yoghurt production, and temperature, time and stages of homogenization are three main factors in this unit operation. In this study, by changing the homogenization conditions, positive results were found to produce yoghurt with the desirable viability of probiotic bacteria, so that by simultaneously increasing the homogenization temperature, time and stages, the probiotic viability improved during fridge storage.

The Production and Delivery of Probiotics: A Review of a Practical Approach

“…Thus, finding the right balance between clinical dose, shelf life, and cost efficiency will in many cases be a function of strain type and pH. Other parameters that influence successful incorporation of probiotics include fermentation temperature (affecting probiotic growth), storage temperature, packaging type (oxygen transmissibility), processing steps such as heat treatment and homogenization, and interaction with other ingredients [41,42]. As the addition of fruits and (increasingly) grains is commonplace in yogurt production, it should be stressed that certain types of fruits and grains can be particularly detrimental to probiotic survivability [43].…”

PromotingLactobacillus caseiandBifidobacterium adolescentissurvival by microencapsulation with different starches and chitosan and poly L-lysine coatings in ice cream

“…Probiotics are defined as live micro‐organisms that confer a health benefit to consumers when administered in adequate amounts (Food and Agriculture Organization and World Health Organization, ). Health benefits of probiotics include maintenance of naturally occurring intestinal microflora, improvement of immune systems, reduction of lactose intolerance in people incapable of digesting lactose, lowering blood cholesterol levels, and antimutation and anticarcinogenic properties (Massoud, Fadaei, Khosravi‐Darani, & Nikbakht, ; Saarela, Mogensen, Fondén, Mättö, & Mattila‐Sandholm, ). In a general classification, lactobacillus and bifidobacterium species constitute the majority of probiotics that are used in food products (Adams, ; Akbarian‐Moghari, Razavi, Ehsani, & Mousavi, ).…”

“…It has been recommended that probiotic products should contain an amount of 10 6 to 10 7 cfu g of the bacterium to offer health benefits (Gibson, Probert, Loo, Rastall, & Roberfroid, ; Massoud et al, ). Some researchers have reported that production processes can lead to a substantial decrease in the added probiotic survival (Cruz, Antunes, Sousa, Faria, & Saad, ; Homayouni, Azizi, Ehsani, Yarmand, & Razavi, ; Kurultay, Öksuz, & Gokcebag, ; Ravula & Shah, ; Sheu, Marshall, & Heymann, ).…”

Bifidobacterium species viability in dairy-based probiotic foods: challenges and innovative approaches for accurate viability determination and monitoring of probiotic functionality

“…HPH is a non-thermal milk preservation method in which the milk is exposed to pressure above 100 MPa (Massoud et al, 2016). Experiments with B. lactis have shown that an increase in homogenization pressure from 100 to 200 MPa, combined with increasing temperature from 50 to 70 • C, led to a significant improvement in the viability of the probiotic in the resultant yogurt (Massoud et al, 2015). The improvement in viability has been attributed to the increase in free amino acids needed for probiotic nutrition (Massoud et al, 2016).…”