Production of pectin from lemon peel powder by ohmic heating assisted extraction process and performance evaluation

Ohmic heating process is known as homogeneous, efficient and fast heating. In this study, it was aimed to analyze pectin extraction from lemon peel using ohmic heating, evaluate the specific pectin production coefficient (SPÜK, mg/kJ) and compare it with traditional pectin production. In order to reveal the effect of the ohmic heating process in detail, pectin extraction was carried out using the traditional method and the change in the physicochemical properties of the resulting pectin substance was compared with the ohmic heating assisted extraction process. The extraction process was conducted at three different temperatures (70, 80, and 90 °C), three different solid-to-liquid ratios (1:30, 1:40, and 1:50 g/ml), and three different extraction retention times (0, 15, and 30 minutes) while maintaining a constant pH of 2 adjusted with citric acid. According to the results, extraction conditions affected pectin yield. An increase in pectin yield was observed as the temperature and extraction holding time increased. In general, the 30-min pectin yields of the ohmic heating-assisted extraction (OIDE) process were found to be similar to the pectin yields obtained from conventional pectin extraction under the same conditions. The performance evaluation of pectin production was made for 90 °C, and the energy efficiency was found to be over 69% for 3 different solid/liquid ratios.It has been determined that the ohmic heating-assisted extraction method allows obtaining pectin with similar quality characteristics with higher energy and exergy efficiency compared to traditional extraction methods. It was concluded that ohmic heating assisted extraction process can be applied as an alternative method for pectin production in different fruit peel powders. It has been stated that the OIDE process can be applied as an alternative to the traditional pectin extraction method.SPSS package program (IBM, USA) was used for this statistical comparison. The thermodynamic energy exergy efficiency, exergy dissipation values, temperature values, and pectin yield were compared during pectin production using the ANOVA test, a multiple comparison test. To compare the differences between the effects of the treatments, the one-way analysis of variance (Post Hoc-Duncan test) was used according to the Completely Randomized Trial Design. The confidence interval was accepted as 0.95 in the statistical evaluation used.