It is known to make food products comprising a biscuit part and a filling part. For example, products having two biscuits and a filling therebetween are known as sandwich biscuits. It is also known for these food products to include in the filling-part an anhydrous filling with live lactic cultures. Anhydrous fillings comprising live lactic cultures are usually produced with yoghurt.
Yoghurt is the product of milk fermentation by symbiotic cultures of Streptococcus thermophilus and Lactobacillus delbrueckii subspecies bulgaricus. Yoghurt is known to have beneficial properties, such as facilitating lactose digestion. These beneficial properties arise from the presence of the two strains of bacteria in large quantities: in particular, the yoghurt has a total cell count of the population of both strains of over 107 cfu/g (cfu: colony-forming unit). However, the shelf-life of yoghurt is usually short; usually less than 2 months for fresh yoghurt. Therefore, yoghurt is usually kept at a low temperature to limit decay of the lactic cultures and organoleptic deterioration.
It is known to make yoghurt powders since they have a longer shelf-life with respect to the organoleptic properties. They are obtained via various drying methods such as freeze-drying and spray-drying. For economic reasons, spray drying is more commonly used. However, spray-drying is more detrimental to lactic culture survival than freeze-drying during production and, thus, results in a greater loss of lactic cultures during drying. Consequently, most of the commercially available yoghurt powders only contain limited amounts of live lactic cultures; lower than 107 cfu/g of yoghurt powder. These are, moreover, typically not sufficiently viable during storage.
US2010136182 discloses a fat-based filling containing starch.
EP2671453 discloses a food product having a filling with a high amount of live lactic cultures.
US2008/305210 discloses cultures encapsulated with compound fat, as well as breakfast cereals coated with the same.
US2009/304864 discloses a powder of fermented milk or yoghurt with a high density of lactic ferments.
WO99/09839 discloses a paste-like composition for use as a filling containing a significant amount of probiotic.
WO2006064959 discloses a lactic acid bacteria-containing chewing gum tablet.
FR2895877 provides a method for producing yoghurt powder with high amount of live lactic cultures, i.e. higher than 5×108 cfu/g of yoghurt powder. This yoghurt powder can be used in fillings for producing sandwich biscuits with a high cell count. The cell count remains high enough to be compliant with the regulatory requirements for yoghurts for up to 7 months at room temperature. However, the products are insufficiently stable to have a shelf-life of 9 months, or even 12 months, which is typical for filled biscuits. In addition, in warmer climates where the sandwich biscuits may be exposed to temperatures above 30° C. for significant periods of time, the shelf stability is unlikely to be sufficient. There is therefore a need to improve the shelf-stability of the composite product.