Development of regression models to study the effect of osmotic dehydration process in Amla (Emblica officinalis) pieces with spices during processing and stability studies

Abstract

This paper aims to study the effectiveness of variables on process development and stability study under atmospheric condition for freeze-dried (FD) and tray-dried (TD) osmotically dehydrated (OD) amla (Emblica officinalis) with spices. Amla pieces were soaked in brine containing fenugreek powder, cumin seed powder, and fresh ginger extracts for OD process. Then, amla samples were FD at −50 °C for 13 h under 10−3 mbar pressure and TD at 50 °C ± 3 °C for 13 h. Multiple regression models were developed for biochemical and microbial parameters of amla. FD and TD samples were packed in 0.05 mm thickness low-density polyethylene pouches and stored at 35 °C ± 3 °C temperature for 60 days. The moisture content of the sample increases slightly with higher regression coefficient for FD (0.046) sample than TD (0.038) sample. The regression models established positive correlation with acidity of TD and FD samples with coefficient 0.004 and 0.005, respectively. It also indicated that 0.002 increase in pH reduces the shelf life of the products. Ascorbic acid and tannin content of the dried samples followed negative nonlinear trend. The paired t test showed no significant difference (p ≤ 0.05) between TD and FD amla pieces during the study period.