Development of pasteurized roselle pickles

Abstract

The limited utilization of roselle in food products had encouraged this study to be done. This study was conducted to develop the most acceptable pickling formulation for roselle pickles. Sensory evaluation was conducted _on six pickling formulations which involved different concentration of sugar (30, 40 and 50 °Brix) and acidity (0.5 and 1.0%). Sensory attributes evaluated were colour, aroma, texture, sweetness and sourness, and overall acceptability. Formulation B, C and F gave no significant different (p>0.05) in the taste and overall acceptability attributes but the texture attribute of formulation C was slightly higher, which was also confirmed by quantitative measurement of texture analysis. Thus, formulation C (50 °Brix, 0.5% acidity) was selected and prepared in four different conditions; fresh pasteurized, fresh unpasteurized, stored pasteurized and stored unpasteurized pickles, and then proceed with physicochemical (pH, ascorbic acid, anthocyanin, energy, ash, fiber, protein, and texture) and microbiological analysis (total viable bacteria, yeast and mould, ·Enterobacteriaceae, Staphylococcus aureus, and coliforms). Fresh roselle calyces were also analyzed for comparison. From fresh calyces to pickles, there were significant increased (p<0.05) in the pH and ash content, significant reduced (p<0.05) in anthocyanin, crude fiber, ascorbic acid and texture, and no significant differences (p>0.05) in energy and protein content. Fresh and stored pickles, both pasteurized and unpasteurized showed significant increased (p<0.05) in pH of pickles and pH of pickling solution, significant reduced (p<0.05) in anthocyanin, ascorbic acid, protein and texture properties. Pasteurized pickles, fresh and stored showed no changes in energy and crude fiber content but decreased significantly (p<0.05) in ash content. Fresh and stored of unpasteurized pickles showed significant decreased (p<0.05) in energy and crude fiber content but showed no changes in ash content. Microbes found in pasteurized and unpasteurized pickles were under safe limit. Since there are not much differences in the physicochemical and microbiological properties of pasteurized and unpasteurized roselle pickles, both fresh and stored, therefore pasteurization process is not a necessary step in the production of roselle pickles.