Effect of lacto-fermentation and freeze-drying on the quality of beetroot evaluated using machine vision and sensory analysis

Abstract

This study was aimed at evaluating the effect of freeze-drying and lacto-fermentation on the texture parameters of images and sensory attributes of beetroots. The samples were imaged using a flatbed scanner, and textures from images converted to color channels L, a, b, R, G, B, X, Y, Z were computed. The discrimination of raw and processed beetroots was performed using models based on textures selected for each color channel. The sensory quality of processed samples was determined using the attributes related to smell, color, texture and taste. The highest discrimination accuracy of 97.25% was obtained for the model built for color channel b. The accuracies for other channels were equal to 96.25% for channel a, 95.25% for channel R, 95% for channel Y, 94.75% for channel B, 94.5% for channel X, 94% for channel L, 92.5% for channel G, 88.25% for channel Z. In the case of some models, the raw and lacto-fermented beetroots were discriminated with 100% correctness. The freeze-dried and freeze-dried lacto-fermented samples were also the most similar in terms of sensory attributes, such as off-odor, attractiveness color, beetroot color, crunchiness, hardness, bitter taste, overall quality. The results indicated that the image parameters and sensory attributes may be related.

Distinguishing Pickled and Fresh Cucumber Slices Using Digital Image Processing and Machine Learning

“…The overall accuracy reached 98.5%. In the available literature, there are reports on the application of image analysis for the quality evaluation of preserved fruit and vegetables, including pickles [19,20] and lacto-fermented beetroot [21,22]. The results of our research confirmed the usefulness of image processing in the evaluation of preserved products.…”

Sustainable Production and Characteristics of Dried Fermented Vegetables

“…Microtomography analysis of vegetables can show the 3D structure of the entire analyzed sample. Rybak et al [29] observed similar results for microtomography of freeze-dried red bell pepper, Bialik et al [40] for kiwi berry, and Ropelewska et al [30] for beetroot raw and fermented.…”

“…It is a low-temperature dehydration process that involves freezing the product, lowering the pressure, and then removing the ice by sublimation. This process preserves the product with the structure of the raw material [29][30][31].…”

Influence of the Salt Addition during the Fermentation Process on the Physical and Chemical Properties of Dried Yellow Beetroot

“…Freeze-drying is an effective method to preserve beneficial probiotic bacteria in fermented products for a longer time. It allows for the preservation of a large amount of bioactive compounds and the survival of some bacteria [43,44]. After freeze-drying, a decrease in the number of bacteria was observed in all the samples.…”