Development of value-added products using the neck flesh of Cape Hake (Merluccius Capensis)

[摘要] ENGLISH ABSTRACT:The focus of this study was the development of food products produced from the neck flesh of Cape hake (Merlucciuscapensis) as a means of adding value to hake heads. The product prototypes that have been developed include curried fishchowder (packaged in stand-up pouches), fish spread (packaged in plastic casings) and Chakalaka hake (packaged in bothcans and retortabie pouches). A formula for fish stock, which was used as a base ingredient in the three product prototypes,has also been standardised. Shelf life testing was regarded an essential part of the development processes for therefrigerated product prototypes i.e. the curried fish chowder and the fish spread. Shelf life determinations involvedmicrobiological testing based on set microbiological standards as well as sensory monitoring and pH testing. Proximatechemical- and mineral analyses were performed on freeze-dried samples of the developed product prototypes.The efficiency of the antimicrobial peptides enterocin 1071 A and 1071 B, as biological preservatives, versus that ofconventional artificial preservatives was evaluated in the fish spread prototype. Three batches of fish spread were prepared:one containing the enterocin crude extract; the second a combination of sodium benzoate and potassium sorbate, while thethird batch containing no preservatives served as the control. Microbiological- and histamine tests coupled withorganoleptic monitoring and pH testing were carried out over a 21-day period. It was concluded that although enterocins1071A and 1071B had some preserving effect in the fish spread, the artificial preservative combination was the superiorpreserving agent. However, neither the biological preservatives nor the artificial preservative combination succeeded inproviding a satisfactory shelf life. The preserving agents used in this study were however not necessarily included atoptimum levels and higher levels could possibly lead to an improved shelf life.The influence of two processing temperatures [121°C (249.8°F) and 116°C (240.8°F)] and two food container types(retortable pouch and can) on the sensory quality characteristics of the Chakalaka hake-prototype was investigated. Theresults indicated that the shorter processing time obtained with a higher processing temperature resulted in a product ofbetter sensory quality. The sensory qualitycharacteristics of Chakalaka hake processed in cans at 121°C were closest tothat considered desirable for the product.

[发布机构] Stellenbosch University