Determination of the Correlation Between Image Parameters and Chemical Properties of Red Sweet Bell Pepper During Fermentation

Abstract The objective of this study was to analyse the image textures and chemical characteristics of red sweet bell pepper samples during the lacto-fermentation process to determine the correlation between these parameters. The raw material of red bell pepper was subjected to spontaneous lacto-fermentation. The imaging by a digital camera and analyses of ascorbic acid, total soluble solids (TSS), acidity, pH, sugars, and carotenoids were performed for raw material and samples after 7, 14, 28, and 56 days of fermentation. The statistically significant decrease in TSS, pH, and the content of L-ascorbic acid, glucose, fructose, total sugars, β-carotene, and total carotenoids of lacto-fermented samples was observed. The strongest relationships with a correlation coefficient (R) of 0.999 were observed for L-ascorbic acid content with image texture bS5SH5DifEntrp and acidity with image texture ZS5SV1InvDfMom of raw and lacto-fermented pepper samples. In the case of carotenoids, the strongest relationship (R=0.999) was observed between image texture XS5SV3DifEntrp and lycopene content. Furthermore, the strong relationships between image textures and the sugar content were obtained reaching R=-0.998 for glucose content and image texture LS4RNLngREmph and R=0.998 for total sugars and BS5SZ5DifEntrp. The results were also used to set the regression equations to estimate chemical properties based on parameters extracted from images.