Control some quality parameters of the natural juice of blueberry with different fruit content

During the study, were analyzed two natural juice with blueberry juice concentrate, packed in Tetra Pak. At the juice were studied these parameters: the technological process of juice production, the sensory characteristics (color, aroma, taste and homogeneity), physical and chemical (pH degree, refraction index, soluble solids degree ° Brix and turbidity expressed with NTU ). The parameters were analyzed in the juice with fruit content of 50% and 25%. From the sensoric aspect the most qualitative fluid resulted with a 50% fruit concentration, from the refractive index content and the degree of ° Brix higher results had 25% fruit juice concentrate, the pH rate was of approximate values while turbidity as a quality juice resulted liquid with fruit percentage 25%. In conclusion we can conclude that the two fluids studied result within the norms for quality regulation, but the above-mentioned changes come from the fruit juice content

ARTIFICIAL SWEETENERS IN VARIOUS FOOD PRODUCTS - QUANTIFICATION AND INTAKE ASSESSMENT

The aim of the study is to determine the content of artificial sweeteners in 133 different food products. The analytical quantification was performed by the application of a reversed-phase, validated, gradient HPLC method, with simultaneous determination of aspartame, acesulfame K and Na-saccharin content. Supelcosil 150 x 4.6 mm, 5µm was used as the stationary phase and mobile phase (buffer 0.1 M NaH2PO4, pH = 2.5 and acetonitrile), at temperature = 26 °C and flow = 1.5 mL/min. The method was applied on: non-alcoholic beverages, chewing gums, sweets, chocolates, confectionery, dietary products, food supplements, fruit yogurt, etc. Depending on the structure of the food, different extraction methods were applied. The assessment of food safety showed irregularity in 21 % of the products, of which 50 % were imported. Some of the products` declarations were not completely translated nor properly labelled. Of the irregular domestic products, 21 % exceeded the maximum permitted quantities of added sweeteners and the rest had irregular labelling. The analysis showed that the most commonly used sweetener was Na-saccharin, which along with aspartame and acesulfame K are most frequently utilized in non-alcoholic beverages. Intake of artificial sweeteners was estimated according to the mean body weight for children, adolescents and adults, under the supposition that the products contained the maximum permitted quantities. The theoretical maximum daily intake of different food products in different population groups indicates the existence of a potential health risk only with continuous "large" intake of products that contain the maximum allowable amounts of artificial sweeteners, especially for the youngest populations

Comparison of quality characteristics of fresh and of dried strawberries

The strawberry is a very importantberries fruit. It can be used fresh or for production of different products, available for consumption during the whole year. The aim of this research was to compare the quality changes of fresh and dried strawberries. For drying were used the strawberries varieties: elsanta, humi grande and mesecharka, from Skopje region. Before drying were applied the following treatments: V0 – not treated, V1 - with vitamin C, V2 - with sugar solution. The drying was performed in Armenian solar dryer. During research were examined the chemical components of fresh and dried strawberries: total dry matter, sugars, total acids, proteins, vitamin C and mineral matter.On solar dried strawberry were performed microbiological analysis according to appropriate regulations. According to this research, the Armenian Solar Dryer is very good in economical and ecological aspect as well as quality properties

DETERMINATION OF VITAMINS AS ADDITIVES FOR FORTIFICATION OF REFRESHING SOFT DRINKS

Soft drinks are sweetened, based on water, usually contain a certain amount of fruit juice, fruit pulp or other natural ingredients and they have a balanced acidity. Their nutritional and energy value is derived mainly from the content of sugars, but besides them there are also mineral elements, vitamins, enzymes and amino acids in minor amounts. Soft drinks are classified as fruit juices and refreshing beverages. Refreshing beverages can be clear or with pulp. The main ingredient is water, then sugar or artificial sweetener, fruit juice or fruit base or plant based extracts or based on cereals, with addition of carbon dioxide and allowed additives in the prescribed amounts. In recent times a trend is to fortify the refreshing beverages with certain vitamins or minerals. Ascorbic acid is commonly added in food as an antioxidant and stabilizer. The vitamins from B group are water soluble and played a significant role in human metabolism. In addition, it is important to consider the amount of the microelements that are necessary to meet our daily needs as nutrients. The research was made on refreshing beverages fortified with vitamins. The analysis was made on 20 different beverages in 2014, 2015 and 2016. The quantitative determination of the water soluble and fat-soluble vitamins in the refreshing beverages was performed by using by HPLC-DAD method. The vitamin C was determined by iodometric method. In the examined samples were usually present the following water soluble vitamins: В1 (from 0.18 to 0.3 mg/100ml), В3 (from 2.40 to 3.20 mg/100ml), В5 (from 0.8 to 1.04 mg/100ml), В6 (from 0.20 to 0,37 mg/100ml) and the vitamin С (from 9.06 to 16.41 mg/100ml), and more rarely were present vitamin В2 (from 0.22 to 0.28 mg/100ml) and the liposoluble vitamin Е (from 0.7 to 1.33 mg/100ml)

CHANGES OF NUTRITIONAL PROPERTIES OF THREE VARIANTS PEPPERS BY PROCESSING OF PICKLED RED PEPPERS

 Blanching was done at 85-90 °C for 5 min. To the pasteurized pepper, acetic acid was added at a concentration of 1.5 % in terms of finished product, which belongs to the low marinated products. Pasteurization is carried out at T 92 °Cfor 30 minutes. The chemical properties were determined by analyzing the following parameters: total dry matter, carbohydrates, proteins, oils, total acids, vitamin C, β-carotene and ash, both in fresh and in pasteurized peppers. Based on the obtained results the quality and nutritional composition were determined. The variety horgosh shows the highest content of total dry matter (11.45 %), vitamin C (138.9 mg/100 g), βcarotene (22.7 mg/100 g), and the highest energy value (41.7 kcal). In the gourp of the pasteurized peppers, the variety of palanechko chudo has been characterized by the lowest average value of total dry matter (7.49 %) and lowest total energy value (24.6 kcal); the variety of kurtovska kapija had the lowest contents of vitamin C (52.1 mg/100 g) and β-carotene (6.09 mg/100 g)

COMPARING THE QUALITY PROPERTIES OF FRESH AND DRIED APPLE FRUIT - VARIETIES PINOVA AND RED DELICIOUS

The quality and the nutritional composition of fresh and dried apple fruits of the varieties pinova and red delicious were tested. The apples were grown in the region of Bitola in the Republic of Macedonia. The fruits were harvested manually after the visual assessment on terrain and after determination of harvesting time. After analyzing the mechanical and chemical properties of the fresh fruit, the fruit was prepared for drying. The treatment of the raw material was done with 0.1 % solution of citric acid and 0.5 % solution of K2S2O5, with time of immersion of five minutes. In order to compare the impact of applied treatments on the tested chemical properties, we also applied a variant of untreated fruit (control). Drying was performed in a chamber dryer from the type S-100, at a temperature between 65 °C to 70 °C for 6 to 8 hours. From the chemical composition of fresh and dried apple fruit, we examined: the total dry matter, total sugars, total acids, vitamin C, pectin, flavonoids, tannins and mineral matter. The fresh fruits from the pinova variety were characterized by better mechanical properties (weight 137.35 g, height 62.56 mm, width 68.78 mm) compared to the fruits of the red delicious variety. In fruits from this variety there were higher values 14.16 % for: total sugars, 0.34 % total acids, flavonoids 2.66 µg/g, tannins 1.39 µg/g and mineral matters 0.25 %. After the analysis of dried apple fruits, the varieties of pinova and red delicious, the higher content of vitamin C was found in fruits treated with 0.5 % solution of K2S2O5. The process of drying in a chamber drier enabled preservation of the chemical properties and getting a quality final product

QUANTIFICATION OF CAROTENOIDS IN SOME VARIETIES OF RED PEPPERS (CAPSICUM ANNUM L.) AND THEIR PROCESSED PRODUCTS

The red pepper (Capsicum annuum L.) is one of the most essential vegetable crops due to multiple ways it can be processed, as well as for the content of the nutritional phytochemicals, such as carotenoids, which are important for human health. Carotenoids are responsible for the pepper’s colour, as natural antioxidants. They are present in relatively high amounts in the ripe fruit and they play a positive role to ensure the colour stability of the final product.This research examined the carotenoids composition of the red pepper varieties: kurtovska kapija, palanechko chudo and horgosh. For each of the varieties, the following preservation technologies have been applied: pasteurization, freezing, and drying. The extraction method of carotenoids was performed by using methanol-dichloroethan and anhydrous Na2SO4. The changes in the carotenoid pigments of examined varieties during processing have been investigated quantitatively by usage of HPLC technique. The HPLC method was performed on stationary phase Nucleosil 100-3 C18, 250 x 4,6 mm, with a flow rate: 0,7 mL/min, and the gradient program with following eluents: methanol, distilled water and a mixture of isopropanol, acetonitrile and methanol. Carotenoids have been detected between 200 and 700 nm. In all of the analyzed samples, 47 peaks of carotenoids were detected, of which 5 were unknown, one was mixed, and 41 carotenoids were identified. The red pepper variety horgosh was found to contain the highest content of total carotenoids in fresh pepper fruits (690,15 µg/g), frozen pepper (587,88 µg/g), pasteurized pepper (575,76 µg/g) and dried pepper (493,94 µg/g)

TOTAL ANTHOCYANINS IN FRESH FRUIT AND COMPOTE OF "OBLACINSKA" SOUR CHERRY (PRUNUS CERASUS L.)

Anthocyanins are secondary metabolites of plants in the flavonoid family. Red and blue fruits are the main sources of anthocyanins, because cyanidin-3-glucoside is one of the most common and gives the red colour of the fruit. They are soluble in water and are 100 % absorbed by the human body. Anthocyanins are powerful antioxidants that protect our body from free radicals. They have a unique ability to resist ultraviolet light and reduce the risk of serious illness. Nutritionists recommend the use of anthocyanins in amounts of 10 to 15 mg per day. Sour cherry (Prunus cerasus L.) contains high levels of anthocyanins that have strong antioxidant and anti-inflammatory properties. In this paper, for the determination of the content of total anthocyanins, fresh fruits from the sour cherry "Oblacinska" variety and compotes of the same variety sweetened with sucrose and stevia are used. Anthocyanins are examined according to the following method: AOAC Official Method 2005.02, Total Monomeric Anthocyanin Pigment Content of Fruit Juices, Beverages, Natural Colorants, and Wines, pH Differential Method. The content of anthocyanins is in the following order: 32.00 mg cyanidin-3-glucoside equivalents / 100 g in fresh sour cherry fruits, 16.10 mg cyanidin-3-glucoside equivalents / 100 g in sour cherry compote with sucrose and 16.12 mg cyanidin-3-glucoside equivalents / 100 g in sour cherry compote with stevia