Sauerkraut juice for new product development: Doctoral thesis for acquiring a doctoral degree of science (Ph.D.) in engineering science and technologies | Skābētu kāpostu sula jaunu produktu izstrādē

Experimental work was carried out in Latvia University of Life Sciences and Technologies, Faculty of Food Technology: scientific laboratory, laboratory of microbiology, biotechnology laboratory, pilot plant for fruit and vegetable processing, laboratory of equipment and processes and chemistry department. Analytical work was also carried out in collaboration with laboratory group J.S. Hamilton. Horizontal spray-drying was carried out in Tecoma Drying Technology SRL, Italy. The hypothesis of the present work – developed dehydrated and concentrated sauerkraut juice is suitable for application in foods. The hypothesis was confirmed by the following thesis: 1. Physico chemical composition of white cabbage is variety dependant and it affects the composition of sauerkraut. 2. Concentration of sauerkraut juice is a suitable technology to obtain a product with high bioactive compound and mineral content. 3. Spray-drying method and carrier agent influence physico chemical composition of dehydrated sauerkraut juice. 4. Dehydrated and concentrated sauerkraut juice affects quality parameters of salad dressings, bread and meat products. The aim of the present work - to develop dehydrated and concentrated sauerkraut juice and evaluate their quality parameters. To achieve the aim, following tasks have been designated: 1. To analyse the variation in the quality parameters of cabbage and sauerkraut juice depending on variety and harvest year. 2. To evaluate quality parameters of concentrated sauerkraut juice produced by different evaporation technologies. 3. To select appropriate carrier agents for horizontal and vertical spray-drying, evaluating their influence on dehydrated sauerkraut juice quality. 4. To evaluate the effect of dehydrated and concentrated sauerkraut juice on salad dressings, bread and meat quality attributes. The work is structured into three chapters. Chapter 1. The theoretical review of the literature describes the characteristics of fresh and fermented cabbage and factors that influence their physicochemical properties. It provides information on the fermentation process. Discusses evaporation methods and encapsulation via spray drying. The review also examines the use of plant-based products in food applications, their sensory characteristics and volatile compounds. Additionally, the review explores in vitro digestion and bioaccessibility of sauerkraut juice and its products. Chapter 2. Description of materials and methods used in this study. Chapter 3. Summarises the results of research on the physicochemical properties of fresh cabbage and sauerkraut juices. It also investigates the effects of different evaporation technologies on the physicochemical properties of sauerkraut juice, and examines the use of horizontally and vertically spray-dried sauerkraut juice with various carrier agents and concentrations. The study also explores the potential applications of sauerkraut juice products in salad dressings, bread, and meat, and evaluates volatile compounds and sensory characteristics. Additionally, the study analyses the bioaccessibility after digestion in vitro.