Development of a nutraceutical confectionery for consumer market using manuka honey and propolis : a thesis presented in partial fulfilment of the requirements for the degree of Master of Technology in Food Technology at Massey University
As consumers have become proactive in health and medical issues, sales of healthy foods have recorded higher growth rate. Therefore, the concept of everyday foods containing ingredients with defined health benefits will significantly influence the types of new foods developed. New Zealanders are among the world's largest consumers of honey, propolis, and other bee products. Further, confirmation of antibacterial properties of a unique NZ honey, manuka honey, has increased its price manifolds. A market research study indicated that potential exists for a familiar confectionery with nutraceutical properties. As a result, jellybeans with added functional properties were developed. Flavour, texture, antibacterial properties, and price were the important attributes to consumers. Lemon flavour was identified as the most acceptable flavour. Jellybeans containing 'active' manuka honey, propolis, were developed using bench top facilities available at the Massey University. The antibacterial properties of manuka honey were found to be stable at 85° C for an hour, and for propolis they were stable at 95° C for 2 hours. In the literature, no procedure was found for testing the antibacterial properties of confectionery products. A 3-step method was developed for the removal of the interfering substances other than sugar, reduction of sugar, and final estimation of antibacterial properties. This gives extract, largely free of interfering substances and antibacterial components in a measurable quantity. The product and process were optimized by Response Surface Methodology (Echip). Using TAXT2 for testing the texture, prototypes were screened down to suitable 8 formulations. Cost was then used as a screening factor to determine the prototypes for sensory testing. Eight prototypes were evaluated with a trained panel as well as consumer panel. External (PREFMAP) and internal preference mapping (MDPREF) was used to interpret the data collected from these two panels. No consensus was reached for the most preferred product. Further, cluster analysis was performed on the results of MDPREF to understand preferences of specific consumers. The study indicated that about half the consumer panel did not have marked differences in liking for the various jellybean prototypes. The product that was preferred by second largest cluster and at the same time well liked by the largest cluster was therefore selected for commercial trial. The product was low in hardness, chewiness, and denseness. The most preferred product was made from 9.2% starch, 5% gelatin, 10.2% honey, 1.8% propolis extract, 20% sugar, and 42% corn syrup. At deposition in the starch the product had 71-72% dissolved solids. The optimized product formulation was scaled up at Cadbury's Confectionery Limited, Auckland. The jellybeans were processed in a Terbraak static cooker. The slurry was cooked to 135-140° C and was then rapidly cooled under vacuum to 95° C. Total solids of slurry were kept at 65-66% due to about 5% moisture evaporation in the plant to get final dissolved solids at 71-72% before deposition in starch. The antibacterial components and lemon flavour was added to the slurry before deposition. The slurry was taken out of the starch at 12-14% moisture and soft panned. The jellybeans were found to have antibacterial properties. The commercially produced developed product was tested with 51 consumers using a Central Location Test (CLT). The developed product had an overall liking comparable to the commercially available jellybeans. About 69% of the panelists showed their willingness to buy this product. The Home Use Test (HUT) held over 8 weeks verified the results of CLT. In HUT 66% of the consumers liked this unique idea and showed preference over the currently available product. About 65% showed willingness to replace the current product. HUT provided validity of the results from CLT and liking of the product did not drop over time (p>0.05) and to the repeated exposure. The results also indicated that immediate use response (Week-0, CLT) for the consumer acceptance could be used as a valid predictor of the extended use responses (Week -8, HUT). As the product's overall liking score is very high (7.5), it is ready for a launch. However, minor changes in the attributes may be considered after market trial. The developed product has antibacterial properties, which were tested by a method developed during the study. As the product offers lot of potential, a food company has shown interest to market this product.