Prirucnik daje pregled znacaja voca i povrca u prehrani, promjena na vocu i povrcu nakon branja, te tehnologije cuvanja svježeg voca i povrca i vrsta i tipova hladnjaca.

A new, selective and accurate direct ultraviolet spectrophotometric method was developed for the determination of L-ascorbic acid in pharmaceuticals. The oxidation of L-ascorbic acid by iodate in an acidic medium was used as a means of correcting for background absorption. The molar absorptivity of the proposed method was found to be 8.71x103 dm3 mol-1 cm-1 at 250 nm. Beer’s law was obeyed in the concentration range of 0.46 – 16.00 μg cm-3 for L-ascorbic acid. The relative standard deviation was 0.67 % for a concentration of 8.00 μg cm-3 of ascorbic acid (n = 7). The ingredients commonly found in vitamin C and multivitamin products did not interfere. The proposed procedure was successfully applied to assays of L-ascorbic acid in pharmaceutical preparations. The results obtained with the proposed method showed good agreement with those given by the titrimetric method using iodine.

The content of the some ingredients, such as proteins, ash, etc. is important in food products, either they are present in raw materials or in final products. As wheat is also very important food raw material, and flour as the fi nal product of milling, it is important to know their specific physical – chemical properties. The importance of knowing the physical and chemical properties of wheat and flour is due to the determination of quality and kind of fl our which is produced after milling process. In this work, some physical – chemical properties are determined and some comparations of characteristics were performed in both wheat and flour. Characteristics that were observed in this work are moisture content, ash content, protein content, Zeleny sedimentation value, gluten content and water adsorption values. On the base of results obtained in this work, some conclusions are made that could be useful for milling industry.

Resistant starch (RS) is increasingly drawing interest due to its potential health benefits and functional properties. It is physiologically important starch fraction, usually present in small amounts in foods. RS is not digested in small intestine, but is fermented by microorganisms in large intestine. Therefore, RS has properties of fibers and prebiotics and can play major role in nutrition. Today, much effort is made to produce chemically modified resistant starches. The aim of this study was to investigate influence of tapioca and maize starch modification by glutaric acid/acetanhydride and succinic acid/acetanhydride mixtures on their digestibility. Starches were modified according to method by Wurzburg and its digestibility was determined by AOAC 2002.02 method. Results showed that, both for tapioca and maize starch, RS/total starch ratio increased approximately by twofold by modification with succinic acid/acetanhydride mixture. Modification of tapioca starch by glutaric acid/acetanhydride mixture resulted in decrease of digestibility, with 1.44 times increase of RS/total starch ratio, while at maize starch it resulted in slight increase of digestibility. These results indicate that modification of starch with succinic acid/acetanhydride mixture has great potential in production of chemically modified resistant starch.

The biochemical oxygen demand (BOD) sensor based on an immobilized mixed culture of microorganisms in combination with a dissolved oxygen electrode has been developed for the purpose of on-line monitoring of the organic pollution of wastewater. A general problem of all commercial BOD sensors is in measuring samples containing heavy metal ions. The result of this study clearly demonstrates the need of the use of heavy metal resistant strains like Alcaligenes Eutrophus, while measuring the BOD of wastewater contaminated by heavy metal.

A simple and highly sensitive direct spectrophotometric method was developed for the determination of L-ascorbic acid. Potassium cyanide (9.21x10-5 mol dm-3) was used to stabilize ascorbic acid in aqueous medium. Th e molar absorptivity of the proposed method, which does not require an extraction procedure, was 1.38x104 dm3 mol-1 cm-1 at 264 nm. Beer’s law was obeyed in the concentration range of 0.26 – 12.0 μg ascorbic acid cm-3. Th e relative standard deviation was 1.40 % for the determination of 8.0 μg ascorbic acid cm-3 (n = 7).

This works presents results of research in influence of pasteurization parameters to the K-sorbat share in pasteurized dried plumb. Control of the K-sorbat share is important for the effect of preservation on one hand and for its influence on health on the other – or for satisfaction of regulations wich limited this part in the conservation. During the wet pasteurization the plumb is treated with hot solution of K-sorbat with aim of additional protection from spoiling. The K-sorbat part in final product is measured by HPLC method. Achived results enable defining the input parameters of wet pasteurization and establishment of legally determined critical limits.

International and national standards tendencies are directed to the safe-for-health food production and processing. Insuring the food safety is achieved with preventive measures and control qualities activities that are determined by GAP, GMP, GHP, GLP. In fruit and vegetables processing there are two most important demands: technological quality and food safety of raw material that are both defined by a comprehensive legislations and international standards. This work presents compressive method of quality system integration in accordance with contemporary standards of ISO (22000), Codex Alimentarius and other legislation for production of safe fruits and vegetables for processing in food industry.

The knowledge of rheological properties of food products is important for characterisation of process and quality parameters, as well as for new products development. Starch and hydrocolloids are often added during processing of different food products to achieve specific properties such as thickening or gelling, adhesion of different food components, film forming, inhibition of crystallisation, etc. One of essential criteria for the choice of hydrocolloids in achieving certain food properties is the compatibility with other food constituents and/or other hydrocolloids. The objective of this work was to investigate the influence of hydrocolloids, carrageenan and locust bean gum (0.5 % w/w) on rheological properties of maize and tapioca starch pastes, and their mixtures. The rheological measurements were carried out with rotational viscometer. Rheological parameters (flow behaviour index and consistency index) were calculated from rheological data. Results showed that hydrocolloids have an important influence on rheological properties of maize and tapioca starch pastes, as well as their mixtures. The greatest influence on viscosity of pastes had addition of locust bean gum to tapioca starch paste.