Standardization and near infrared reflectance spectroscopy based quality evaluation of thermally processed tender jackfruit (Artocarpus hetero phyllus L.)

Abstract

The present study examined thermal processing in tin free steel cans (TFS) and near infrared reflectance spectroscopy (NIRS) techniques for preservation and rapid characterization of tender jackfruit, respectively. In the thermal processing study, the effect of 16 treatments with different time-temperature combinations on physicochemical and microbiological attributes of canned tender jackfruit were examined. Accordingly, pasteurization at 90 o C for 19 min (F = 60 min) and sterilization at 121 o C for 8 min (F 0 = 3 min) were identified as the best treatments. During 7 months of storage, these treatments yielded microbiologically safe tender jackfruit with no significant (p < 0.05) change in titrable acidity, total soluble solids, carbohydrate and crude fibre contents. In both pasteurization and sterilization treatments with/without preservatives, quality and sensory attributes of canned tender jackfruit were comparable. Hence, the study endorse the use of any of the standardized thermal processing treatments even without preservatives for safe storage of tender jackfruit. The NIRS study was the primary attempt to characterize tender jackfruit (fresh and thermal processed) using its spectral reflectance (R * ) within 400-2500 nm wavelength range by means of partial least square regression (PLSR) algorithm. Based on cross- validation of PLSR models, the study have identified a) second derivative of R * in 7012450 nm as the best pre-processing and wavelength combination for the estimation of quality attributes of fresh tender jackfruit, b) spectral measurement of intact tender jackfruit samples outperform grated counterparts, c) dry spectra of thermal processed tender jackfruit yield superior results than wet spectra, d) DLP NIRscan Nano for cost effective characterization of inter component (skin, tendril and core) variability of fresh tender jackfruit with regard to total flavonoid and phenol contents. The overall results of the analyses advocates the use of NIRS for a rapid, reliable, non-destructive and non- invasive quality assessment of tender jackfruit.