Spray‐drying for the production of dried cultures

Abstract

This review emphasises the importance of spray‐drying as an under‐used but promising technique to preserve viable and active starter cultures and also, potentially, probiotic cultures. The knowledge concerning the production of spray‐dried starter cultures is discussed. Different drying techniques and micro‐organisms have been investigated for their survival through the drying process. During drying and subsequent storage in the dried state, bacteria are subjected to several stresses, which have already been described as causing damage to cells, leading to the loss of cellular viability and activity. Some studies found that several factors/strategies can confer improved cellular viability.

Diversity in Robustness of Lactococcus lactis Strains during Heat Stress, Oxidative Stress, and Spray Drying Stress

“…During spray drying, cultures are exposed to severe heat and oxidative stress (6,7), typically resulting in lower survival rates of starter cultures than freeze-drying (3,4). Therefore, freeze-drying is currently the most often applied industrial drying method (3)(4)(5). However, spray drying appears a more cost-effective and energy-efficient drying alternative for the preservation of starter cultures (3)(4)(5), providing strains that display high robustness under the stresses encountered in this process can be identified.…”

“…Therefore, freeze-drying is currently the most often applied industrial drying method (3)(4)(5). However, spray drying appears a more cost-effective and energy-efficient drying alternative for the preservation of starter cultures (3)(4)(5), providing strains that display high robustness under the stresses encountered in this process can be identified. This appears feasible, as studies on stress phenotypes typically result in highly strainspecific robustness phenotypes, e.g., for the gastrointestinal survival of Lactobacillus plantarum strains (8) and the robustness of several Lactobacillus strains during acid, alkaline, heat, oxidative, osmotic, detergent, and starvation stresses (9).…”

“…Nowadays, many of these processes have been industrialized, and fermentation is typically initiated by the addition of starter cultures, which contain high concentrations of one or multiple LAB strains (1,2). As starter cultures require metabolic activity to contribute to the taste and texture of the fermentation end products, there has been an increasing industrial interest in studying robustness phenotypes during industrial production and processing (1), which involves preservation by either freezing or drying techniques (3)(4)(5). The major disadvantages of frozen starter cultures are the inconvenience and costs of transport and storage at low temperature, and, therefore, drying techniques are preferred (3)(4)(5).…”

“…As starter cultures require metabolic activity to contribute to the taste and texture of the fermentation end products, there has been an increasing industrial interest in studying robustness phenotypes during industrial production and processing (1), which involves preservation by either freezing or drying techniques (3)(4)(5). The major disadvantages of frozen starter cultures are the inconvenience and costs of transport and storage at low temperature, and, therefore, drying techniques are preferred (3)(4)(5). During spray drying, cultures are exposed to severe heat and oxidative stress (6,7), typically resulting in lower survival rates of starter cultures than freeze-drying (3,4).…”

Evaluación de la Estabilidad y Viabilidad de Dos Cepas Probióticas Microencapsuladas por Lecho Fluidizado

“…28 Nº 6 2017mejores resultados con leche descremada para la bacteria P. agglomerans, esto debido a la capacidad de este medio complejo para reparar células dañadas y mejorar la recuperación final después del proceso de secado. Esto fue corroborado por Silva et al (2011), que afirman que la leche descremada es capaz de prevenir daños en las células mediante la estabilización de la membrana celular, ya que contiene proteínas que proporcionan un recubrimiento protector.…”