Probiotic functional foods: Survival of probiotics during processing and storage

• Low pH is a major factor that restricts growth and stability of probiotic bacteria.
• Molecular oxygen is detrimental to growth and survival of probiotics especially during storage period.
• The process of microencapsulation has been used for improving the viability of probiotics in fermented food products.
• Antioxidant compounds could be used to limit negative effects of oxygen exposure on probiotic bacteria.
• Mild heat treatment before spray drying may enhance cell survival during storage.

Probiotic foods are reported to provide several health benefits, as they help in maintaining a good balance and composition of intestinal flora, and increase the resistance against invasion of pathogens. The demand of probiotic functional foods is growing rapidly due to increased awareness of consumers about the impact of food on health. Development of foods with adequate doses of probiotics at the time of consumption is a challenge, because several factors during processing and storage affect the viability of probiotic organisms. The presence of probiotics in food products may also adversely affect their quality and sensory properties. Several attempts have been made during the last few decades to improve the viability of probiotics in different food products during their production until the time of consumption. Major emphasis has been given to protect the microorganisms with the help of encapsulation technique, by addition of different protectants, and by alteration of processing and storage conditions. This contribution provides an overview of probiotic foods, factors responsible for survival of probiotics, and advance technologies used to stabilize their viability during processing and storage.