Athirah Dayang Nur, Asaruddin Mohd Razip, Bhawani Showkat Ahmad, Simbas Aldrin Felix, Jack Kho Swen
Universiti Malaysia Sarawak, Samarahan, Sarawak, Malaysia.
BMC Res Notes. 2025 Mar 31;18(1):136. doi: 10.1186/s13104-024-07039-5.
This study aimed to evaluate the effectiveness of the E' food grade preservative - potassium sorbate (E202) and sodium metabisulfite (E223) in an aqueous form, and impact of the timing of preservative addition on the shelf-life, sugar and reducing sugars levels, organic acids content and microbial growth of nipa palm sap.
The pH, sugar and reducing sugars levels, organic acids content, total bacterial count (TBC) and sensory characteristics of the sample were determined. The results showed that the treated samples were able to slow down the pH and sucrose content from dropping during storage. Sample A had lactic acid at 0.93 ± 0.01 g/L and acetic acid at 0.05 ± 0.0.1 g/L, while Sample B had 0.97 ± 0.02 g/L and 0.07 ± 0.01 g/L, respectively, both lower than the control (1.10 ± 0.01 g/L and 0.09 ± 0.02 g/L). Sample A with TBC of 1.03 (± 0.08) x 10 CFU/mL was able to inhibit microbial growth better than Sample B, 1.14 (± 0.13) x 10 CFU/mL. Preservative application prior to tapping was shown to be more successful in preserving the quality and shelf-life of nipa palm sap. This approach is likely preventing early microbial activity and fermentation without the need of proper packaging, preserving the freshness and quality of the sap more effectively than adding the preservative after collection.
本研究旨在评估食品级防腐剂山梨酸钾（E202）和焦亚硫酸钠（E223）水溶液的有效性，以及添加防腐剂的时间对尼帕棕榈树液保质期、糖和还原糖水平、有机酸含量及微生物生长的影响。
测定了样品的pH值、糖和还原糖水平、有机酸含量、总细菌数（TBC）及感官特性。结果表明，处理后的样品能够减缓储存期间pH值和蔗糖含量的下降。样品A的乳酸含量为0.93±0.01 g/L，乙酸含量为0.05±0.01 g/L，而样品B的乳酸含量为0.97±0.02 g/L，乙酸含量为0.07±0.01 g/L，均低于对照组（1.10±0.01 g/L和0.09±0.02 g/L）。样品A的总细菌数为1.03（±0.08）×10 CFU/mL，比样品B（1.14（±0.13）×10 CFU/mL）更能有效抑制微生物生长。结果表明，在采割前施用防腐剂在保持尼帕棕榈树液的质量和保质期方面更为成功。这种方法可能无需适当包装就能防止早期微生物活动和发酵，比采后添加防腐剂更有效地保持了树液的新鲜度和质量。
