背景:新鲜提取的甘蔗汁是微生物发酵和褐变反应的理想底物。本研究是关于脉冲光(PL)处理在保留主要生物活性物质的情况下改善微生物稳定性的潜力的第一份报告。探索了在不同电压水平(2.1-2.7kV)和脉冲数(100-200)下的PL处理。本研究旨在探讨PL加工对甘蔗汁品质的影响,生物活性成分和微生物负荷。
结果:微生物负荷,如好氧中温菌,酵母和霉菌,和总大肠杆菌,在2.7kV下进行强PL处理的果汁样品中减少到低于1log菌落形成单位mL-1。即使在PL工艺参数的极端水平下,甘蔗汁的总色差的最大值也低于4.0。与未加工的果汁相比,总酚类(Folinciocalteu试剂测定)和总抗氧化能力(2,2-二苯基-1-吡啶酰肼自由基清除测定)的减少限制为6%和16.7%,分别,当在2.7kV/200脉冲下处理时。在所有经处理的样品中,果汁的pH和总可溶性固形物保持不受影响。在所考虑的工艺参数中,发现处理电压显着影响质量参数和微生物负荷。
结论:在2.1kV/170脉冲下进行PL处理可得到最佳处理的果汁,其微生物负荷低于允许的极限和期望值0.77。结果表明,PL处理对于增强微生物稳定性和保持甘蔗汁的生物活性成分是有效的。此外,本研究的结果有望为进一步深入研究PL处理对甘蔗汁关键质量属性和保质期的影响铺平道路。该技术将有助于不同的利益相关者采用,包括食品加工行业的制造商和零售商。©2024化学工业学会。
BACKGROUND: Freshly extracted sugarcane juice is an ideal substrate for microbial fermentation and browning reactions. The present study is the first report on the potential of pulsed light (PL) processing in improving microbial stability with the retention of major bioactive. PL processing at different levels of voltage (2.1-2.7 kV) and number of pulses (100-200) was explored. The present study aimed to investigate the impact of PL processing on the quality of sugarcane juice, bioactive composition and microbial load.
RESULTS: The microbial load, such as aerobic mesophiles, yeast and mold, and total coliform, was reduced to below 1 log colony-forming units mL-1 in juice samples subjected to intense PL treatment at 2.7 kV. The maximum value of the total color difference of the sugarcane juice was below 4.0, even at extreme levels of PL process parameters. In comparison with the unprocessed juice, the reduction in total phenols (Folin ciocalteu reagent assay) and the total antioxidant capacity (2,2-diphenyl-1-picrylhydrazyl free radical scavenging assay) was limited to 6% and 16.7%, respectively, when treated at 2.7 kV/200 pulses. The pH and total soluble solids of the juice remained unaffected in all the processed samples. Among the process parameters considered, the treatment voltage was found to significantly affect the quality parameters and microbial load.
CONCLUSIONS: PL processing at 2.1 kV/170 pulses gave an optimally processed juice with a microbial load below the permissible limit and desirability value of 0.77. The results suggest that the PL treatment is effective for enhancing the microbial stability and maintaining the bioactive components of the sugarcane juice. Furthermore, the outcomes from the present study are expected to pave the way for further in-depth investigation of the effect of PL treatment on the critical quality attributes and shelf life of sugarcane juice. The technology will be useful for adoption by different stakeholders, including manufacturers and retailers in the food processing sector. © 2024 Society of Chemical Industry.