Page 360 - Demo

364 PROCEEDINGS OF INTERNATIONAL SCIENTIFIC CONFERENCE ON APPLIED BIOTECHNOLOGYSterilisation is crucial in tea production to eliminate impurities and exotic microorganisms before fermentation. Therefore, assessing the effects of different sterilisation methods is essential. The experiments were conducted following 2.2.1, with variations in sterilisation solutions (5% NaCl, 0.02% NaClO, and no sterilisation). The statistical results are presented in the figure above.For the total acid content, the sample without sterilisation had the highest acidity, likely due to the presence of exotic microorganisms that produced unwanted secondary products and chemicals. Cascara tea using 5% NaCl showed a good balance in total acid content, contributing to a high-quality product. The batch utilised 0.02% NaClO showed a significant decrease in total acid content, possibly due to a strong oxidation effect and the breakdown of organic acidic compounds. Regarding the total vital count, the non-sterilised test had the highest concentration of aerobic microorganisms and yeast due to the growth of unwanted exotic microorganisms, affecting the overall quality. The Cascara tea treated with 5% NaCl reduced the total viable counts as NaCl changed the osmotic pressure in the exotic microorganisms but still achieved the highest sensory quality, while the product treated with 0.02% NaClO illustrated a substantial decline in microbial counts due to strong oxidation properties but had negative impacts on other indicators and sensory scores. The non-sterilised sample had the highest total phenolic content. The 5% NaCl treatment maintained a balanced level of total phenolic content, which is important in preserving flavour and sensory quality. The 0.02% NaClO tea demonstrated a significant reduction in phenolic content, indicating that NaClO may affect the structure and chemical composition due to strong oxidation.