Innovation

Combine Method of Hurdle Technology: Juice Innovation
In circumstances where thermal processing is impractical, minimal processing employing hurdles is called for. The hurdle principle is based on the premise that while any single barrier to microbial growth may be inadequate for desired protection, a number of barriers together can enhance product stability (Figure 8.1).
Thus good sanitation is the first barrier to reduce microbial load; low storage temperature further retards growth. An acid environment of pH less than 4.5 (ideally less than 3.5) restricts the growth of many organisms. Fortunately most juices are acid, or amenable to acidification. The exclusion of oxygen is an additional barrier. (Although anaerobic conditions are dangerous with low acid foods and can even set the stage in high acid products for anaerobic spoilage organisms, i.e. yeast, lactic acid bacteria, etc.) Antimicrobial substances, either natural or chemical preservatives, also assist. Proper use of hurdles can appreciably lengthen shelf life of unpasteurized juices without unduly affecting quality.
Minimal processing is the strategy by which a number of hurdles are combined to effect near "fresh" juice characteristics. Although the sensory quality may approximate that of the unprocessed product, the term "fresh" cannot be used. The ubiquitous network of refrigerated and frozen production, storage and transportation facilities, including home units, encourages minimal processed juice products. Thus, even the slightly less fresh flavour exhibited by pasteurized juice is not acceptable to some. In developed countries fresh squeezed, refrigerated juices continue to capture sales from frozen concentrates despite a substantially higher price and shorter shelf life (Table 8.1, Figure 8.2). Convenience and the closer-to-natural image apparently justify the 30 to 50 percent price premium and bulky storage requirements of these ~85 percent water drinks.