Chitosan-based edible coatings were used to prolong the shelf-life of strawberries stored at 20 C and 35 e40% RH. Strawberries were coated with four different coating formulations (chitosan as monolayer, three layer coating consisting of separate beeswaxechitosanebeeswax layers, three layer coating where chitosan was crosslinked with sodium tripolyphosphate, TPP, and composite). The effectiveness of the coatings was evaluated by the changes of several parameters: fungal infection, weight loss, respiration rate, skin and flesh color, firmness, pH value, titratabale acidity, soluble solids content, reducing sugars content and sensory evaluation. The coatings, especially the three-layer coatings, significantly decreased the senescence and weight loss of the fruits. They modified the respiration rates of the strawberries and slowed down their metabolism as shown by the retention of the color and the texture of the tissue. Sensory evaluation of the coated strawberries showed that the chitosan and composite coatings gave better visual appearance and taste and were therefore more preferable by 90% of the judges than the three-layer coatings, even though the later had higher protective effect of the overall quality of the strawberries.

The low cost raw material, apple variety Idared, was turned into value-added product, apple chips. The apple chips were produced in a two-step process consisting of osmotic treatment and conventional drying. Osmotic treatment was carried out in 40 % glucose solution at room temperature, followed by convective drying at 105°C, till reaching water activity of 0.3. Mechanical properties of the apple chips measured by compression and penetration tests were correlated with the sorption properties. The low browning index, 25.5 and high whitening index, 63.7, proved the good retention of the color of the apple chips. The instrumental characteristics of the apple chips were correlated with the sensory characteristics of the product. The new product was accepted by the 95 % of the panelists. The stored apple chips under modified atmosphere showed no significant changes in the quality parameters over 6 month period.

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Chitosan-based edible films were prepared and subjected to cross-linking reactions using sodium tripolyphosphate and/or to beeswax coating on both films interfaces. In addition, chitosan-beeswax emulsion-based films were produced. The goal of these modifications of the chitosan films was the improvement of their barrier to water vapor and to decrease their affinity to liquid water maintaining or improving the mechanical and optical properties of the original chitosan films. The cross-linking with tripolyphosphate decreased both the water vapor permeability and the water absorption capacity to about 55% and 50% of that of the original chitosan films, respectively. However, there was an increase in the films stiffness, revealed by the increased Young modulus from 42 kPa up to 336 kPa. The multilayered wax-chitosan-wax films exhibited a similar improvement of the barrier properties to water vapor, with the advantage of maintaining the mechanical properties of the original chitosan films. However, these wax-coated films showed a higher water absorption capacity, which is believed to be a consequence of water entry into small pores between the film and the wax layers. Regarding the film samples subjected to cross-linking and further coating with beeswax, a similar behavior as the uncoated cross-linked films was observed. The emulsion-based composite films were characterized by a substantial decrease of the water vapor permeability (40%), along with a decrease in their stiffness. Regarding the optical properties, all films presented a yellowish color with similar values of lightness, chroma, and hue.

The potential application of xylitol, as low energy alternative sweetener, was investigated in baked products. Xylitol was used as sole sweetener in home made cookies, the properties of which were compared to products containing sucrose and glucose. The sensory properties were evaluated by discrimination, descriptive, and affective tests. The storage time of one and two weeks, both at 4-6°C and at 20-22°C did not show significant impact on the flavor and texture properties of all cookies. After being stored for 3 months at 20-22°C, the samples with sucrose showed statistically significant differences in crunchiness (P < 0.001) and tenderness (P < 0.01). The cookies prepared with xylitol, apart from significantly reducing the aftertaste (P < 0.001), did not exhibit any other significant changes. Statistically significant differences (P < 0.001) were detected between the samples containing sucrose and xylitol in all texture attributes and in the cooling effect, but no difference in the sweetness was observed. The most chosen categories on the hedonic scale for the xylitol cookies were "like slightly" and "like moderately," while the extreme categories were not ascribed. Compared to the cookies with sucrose and glucose, xylitol cookies had least microbial loads at different storage and temperature regimes and were microbiologically safe with tendency to have longer shelf-life than the other products.

A probiotic strain Lactobacillus plantarum PCS26 was used to ferment Jerusalem artichoke juice. Growth kinetics of the bacterial strain was followed during juice fermentation both in flask and in laboratory fermentor. Jerusalem artichoke showed to be an excellent source of nutrients for L. plantarum PCS26 growth. The culture grew very well reaching more than 10 10 cfu/ml in just 12 h. The pH changed from the initial 6.5 to 4.6 at the end of fermentation. The culture hydrolyzed fructooligosaccharides present in the Jerusalem artichoke juice, yielding fructose which was presumably consumed along with the malic acid as energy and carbon source. Lactic acid was the main metabolite produced in concentration of 4.6 g/L. Acetic and succinic acid were also identified. Sensory evaluation of the fermented Jerusalem artichoke juice and its mixtures with blueberry juice showed that the 50/50 % v/v mixture would be very well accepted by the consumers. Above 80 % of the panelists would buy this drink, and over 60 % were willing to pay more for it. Culture survivability in the fermented juices during storage at 4-7°C was assayed by the Weibullian model. The product shelf-life was extended from 19.70 ± 0.50 days of pure Jerusalem artichoke juice to 35.7 ± 6.4 days of the mixture containing 30 % blueberry juice.

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Studies on the development of non-dairy probiotic foods and beverages are continuously emerging. Fruit and vegetable juices have proved to be promising carriers or growth media for probiotics. In this study, apple juice was explored as a growth medium for cultivation of the probiotic Lactobacillus plantarum PCS 26 strain. Fermentation was performed with free and Ca-alginate-embedded bacteria at different initial pH values, as well as with whey supplementation as a growth enhancer. During the fermentation, growth kinetics, pH, sugars consumption and lactic acid production were measured, along with culture survival during storage. The best results were achieved by fermentation at an initial pH of 4.2, reaching maximal cell density of 2.5 x 10 9 CFU/mL and a final pH of 4.7 after 24 h. Malolactic conversion was commenced by the strain as energy yielding mechanism, thereby lowering the consumption of sugars below the limit of determination by the analytical method used. Apple juice supplementation with 5 %v/v whey accelerated fermentation kinetics and resulted in a higher viable bacterial count. In contrast, entrapment of cells into Ca-alginate caused significantly slower growth, yielding a lower bacterial count at the end of fermentation (3.2 x 10 6 CFU/mL). However, stability during storage of the fermented product at 4-7°C improved, and the survival of immobilized bacteria, estimated by Weibullian model, increased to 32.1±5.2 days compared to 22.0±0.68 days in the free-cell fermentation. In conclusion, apple juice was found to be an appropriate medium for fermentation by probiotic Lactobacillus plantarum PCS 26, resulting in a functional drink with potentially good sensory acceptance and shelf life.