ABSTRACT
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. CONCLUSION: 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.
ABSTRACT
The vacuum impregnation (VI) process parameters (vacuum pressure = 20-60 kPa; VI temperature = 35-55°C; concentration of the sucrose solution = 40-60 °Brix; and vacuum process time = 8-24 min) for pineapple rings were optimized based on the moisture content (MC), water loss (WL), solids gain (SG), yellowness index (YI), and total soluble solids (TSS) content of pineapple rings using response surface methodology (RSM). A relationship was developed between the process and response variables using RSM and artificial neural network (ANN) techniques. The effectiveness of VI was evaluated by comparing it with the osmotic dehydration (OD) technique. The optimum condition was found to be 31.782 kPa vacuum pressure, 50.441°C solution temperature, and 60 °Brix sucrose concentration for 20.068 min to attain maximum TSS, YI, SG, and WL, and minimum MC of pineapple rings. The R2 values of RSM models for all variables varied between 0.70 and 0.91, whereas mean square error values varied between 0.76 and 71.58 and for ANN models varied between 0.87-0.93 and 0.53-193.78, respectively. Scanning electron micrographs (SEM) revealed that parenchymal cell rupture was less in VI than in OD. The VI pineapple rings exhibited more pores and high SG, as compared to OD, due to the pressure impregnation. Spectroscopic analysis affirmed that the stretching vibrations of intermolecular and intramolecular interactions were significant in VI as against OD. The VI reduced the drying time by 35% compared to OD, with the highest overall acceptability score and lower microbial load during storage. PRACTICAL APPLICATION: Pineapple is a perishable fruit, which necessitates processing for extended shelf life. This study highlights the potential of the vacuum impregnation process as a promising alternative to conventional preservation methods such as osmotic dehydration for pineapples.
Subject(s)
Ananas , Dehydration , Vacuum , Desiccation/methods , Water/analysis , SucroseABSTRACT
The effect of energetic neutral argon (EAr) atoms on the short and long-term retrogradation was studied, and the retrograded starch was used to prepare bioplastic films for better mechanical and barrier properties. Kithul starch showed higher short and long-term retrogradation after treatment. The EAr atoms treatment increased amylose content and amylose leaching; it facilitated the short-term retrogradation. The more pronounced effect of long-term retrogradation in starch after treatment increased the enthalpy of retrogradation (ΔHR), hardness, and syneresis and decreased the light transmittance and freeze-thaw stability. Bioplastic films made from retrograded starch after EAr atoms treatment exhibited significantly (p ≤ 0.05) higher relative crystallinity; it could be attributed to the higher starch retrogradation after cold plasma treatment. The films of retrograded EAr atoms treated starch showed higher mechanical strength and barrier properties. These results revealed that bioplastic films from retrograded EAr atoms treated starch could potentially substitute the single-use petroleum-based packaging films.
