The main purpose of the present experiments was to investigate the effect of various hydrogen peroxide (H2O2) concentrations and for various lengths of treatment on the total carotenoid, β–carotene content, colour intensity and microbiological safety on the fresh shredded carrots. Shredded carrots were dipped in 0.5, 1.0 and 1.5% H2 O2 water solution for 30 ± 1s, 60 ± 1s and 90 ± 1s. Negative effect of H2 O2 on β–carotene content and colour parameters of analyzed shredded carrots samples was not detected. In carrots treated with H2 O2 (p = 0.008) for 60 – 90s the total content of carotenoids significantly decreased during treatment compared to untreated carrot samples. There was significant difference (p is less than 0.05) observed between treated and non–treated shredded carrot samples on the total bacteria count. It was possible to reduce significantly (p is less than 0.05) the content of yeasts and mould up to 99.99% by shredded carrots treatment with 1.5% hydrogen peroxide water solution for 30 ± 1s. In the non–processed carrots E.coli was detected; however, it was possible to destroy E.coli by treating carrots with 0.5% H2 O2 water solution for 30 ± 1s. Considering all experimentally obtained results, we have concluded that fresh shredded carrots could be treated in water with the addition of hydrogen peroxide 1.5% for 30 ± 1s to maintain quality.

Fruits and vegetables are a major source of antioxidants. The aim of current research was to study and compare the antiradical activity, the total polyphenol content (TPC) and the total flavonoid content (TFC) in dried carrots (Daucus carota), pumpkins (Cucurbita maxima), leeks (Allium ampeloprasum var. porrum) and black radish (Raphamussativus) using a traditional convective drier and a microwave-vacuum drier. For each vegetable steaming as pre-treatment was used. Vegetables were harvested in Latvia in 2012, gathered when ripe and then dried. Analyses were made in Latvia University of Agriculture, Faculty of Food Technology laboratories. The total polyphenol content was determined by the Folin- Ciocalteu method and the total flavonoid content - using spectrophotometric method. The antiradical activity was analyzed by the 2,2-diphenyl-1-picrilhydrazyl (DPPH) assay. The results of experiments demonstrate that the total amount of polyphenols ranged from 98.97 to 623.70 mg gallic acid equivalent (GAE) 100 gE-1 in dry weight and the total amount of flavonoids ranged from 40.32 to 100.23 mg catechin equivalent (CE) 100 gE-1 in dry weight. The value of DPPH antiradical activity for vegetable samples ranged from 6.10 to 45.14 percents.

The traditional consumption of citrus juices as a breakfast beverage has historical ties to obtaining one’s daily requirement of vitamin C. Vitamin C is one of the most important vitamins found in citrus juices, including orange juice. The aim of the study was to determine the effect of processing and storage on the content of vitamin C in orange juice varieties of ‘Valencia’ and ‘Navel’ of orange juice. The content of vitamin C (mg 100 gE-1) was determined with the iodine method in freshly squeezed orange juices and in pasteurized and packaged in aseptic bags orange juices of ‘Valencia ‘and ‘Navel’ variety, after processing and during 24 weeks of storage at 20 ± 1 °C and 5 ± 1 °C. The study results showed that the average content of vitamin C in freshly squeezed orange juice ‘Valencia’ was found at 33.56 mg 100gE-1 but in freshly squeezed orange juice ‘Navel’ the content of vitamin C was higher than in ‘Valencia’ variety orange juice average at 46.18 mg 100gE-1. The loss of vitamin C for both orange juices on average about 7% during processing The storage study showed that after 24 weeks of storage at 5 ± 1 °C and at 20 ± 1 °C, in pasteurized orange juice ‘Valencia’ the content of vitamin C decreased by 9.83% and 19.73 respectively. In the pasteurized orange juice ‘Navel’ the content of vitamin C decreased by 8.53% and 15.24% respectively.

The aim of the present study was to analyse and compare camel milk powder quality and functional properties produced with spray-drying and freeze-drying techniques. Freeze-drying is recognized as an advanced method for the production of high-quality dried products, but it has been a costly process for production of camel milk powder. Spray-drying and freeze-drying of camel’s milk demonstrated that the nutritional characteristics of this product basically remained unchanged compared to fresh milk. The differences were found analysing flowability, solubility and hygroscopicity of camel milk powder samples obtained with freeze-drying and spray-drying technique. Analysed quality indices of camel milk demonstrated that spray-drying has lower impact on camel milk powder physical properties in comparison with freeze-drying.

Honey is a naturally supersaturated sugar solution, which tends to crystallize. The crystallization of honey can lead to unwanted fermentation that can have a negative impact to honey quality. The production of honey powder could be an alternative method to prevent honey from fermentation. Honey powder could be used as alternative substitute to liquid honey that would allow to use this product more widely in the food industry. α-amylase activity is one of the most important parameters to evaluate the quality of honey. The aim of this study was to investigate the effect of freeze-drying and spray-drying on honey α-amylase activity. Detection of α-amylase activity was carried out by spectrophotometric method. High-performance liquid chromatography was used to determine the content of hydroxymethylfurfural in the powders. The obtained results showed that both drying methods had a negative impact to the enzyme activity in the samples. The lowest activity of α-amylase (8.3 DN) was measured in the spray-dried honey powder. Concentration of hydroxymethylfurfural (HMF) in the powders did not exceed required concentration 40 mg kgE−1.

The aim of this review was to summarize available bibliography on the possible applications of high pressure processing in dairy industry, the effect of this non-thermal treatment on bacterial microflora and milk constituents. Traditional thermal treatments applied to milk processing lower nutritional quality because many nutrients are heat labile. To overcome this problem, several non-thermal processing technologies including high hydrostatic pressure (HHP) processing have been developed. Pressures between 400 and 600 MPa inactivate microorganisms including food-borne pathogens; however, high pressure (HP) injured bacteria in milk during storage can recover. All enzymes are inactivated only at pressures of 800 MPa. During HHP the casein micelle size decreases, whey proteins are denaturated, the level of free fatty acids increases. These characteristics indicate that for better understanding and application of HPP in dairy industry research should be done to offer the numerous practical applications to produce microbially safe, minimally processed dairy products with improved performances, and to develop novel dairy products of high nutritional and sensory quality and increased shelf life.