Introduction. The research aim-to determine the effect of two herbal mixtures on herb bread properties. The influence was established of the herbals on the total phenolic content and antioxidant activities of herbal mixtures, herbal-flour mixtures and herb breads. Materials and methods. It was used two herbal mixtures (1-thyme, oregano and lemon balm; 2-thyme, oregano, lemon balm and fenugreek) with wheat flour for herb bread production. Total polyphenol content was determined following the Folin-Ciocalteu method. The antioxidant activities of sample extracts were evaluated by four methods: ABTS •+ , CUPRAC, FRAP and DPPH assay. Results and discussion. The highest total phenolic content from all investigated herbs showed oregano (30.43 mg GAE/g dw), herbal mixtures 1 and herbal mixtures 2-19.18 mg GAE/g dw and 17.47 mg GAE/g dw, respectively. In herbal-flour mixture and prepared breads the level of total phenolic content were in the range from 0.31mg GAE/g dw to 0.37 mg GAE/g dw. Therefore, the content of these bioactive compounds didn`t changed significantly during the baking process. The highest antioxidant activity of herbal mixtures, herbal-flour mixtures and breads were obtained by two of the used methods-ABTS and FRAP assay. The highest antioxidant potential was demonstrated by herbal mixture 1 consisted of 3 herbs-16829.73 mM TE/100 g dw, followed by the herbal mixture 2 with 4 herbs-14693.75 mM TE/100 g dw, respectively, both evaluated by the ABTS method. For the FRAP method, the antioxidant activity values were: 15997.65 mM TE/100 g dw for the herbal mixture 1 with 3 herbs and 14136.82 mM TE/100 g dw for the herbal mixture 2 of 4 herbs. Conclusions. Herbs added to flour increased the total phenolics and antioxidant values of flour-mixtures and breads. Insignifiant differences in the antioxidant potentials were observed between breads with three and four herbs.

The aim of this paper is to analyze the effect of replacing part of wheat flour (4, 8, 16, 24 and 32% for cookies and 4, 6, 8 and 10% for sponge cake) and to measure influence on the color of the cookies and the sponge cake with apple skin powder and grape pomace powder, respectively. The cookies were produced according to the AACC 10-50D method with some modifications, and the sponge cake was produced according to the method presented by Velioğlu et al., 2017 with some modifications. Digital image analysis and colorimeter were used to determine the colour change of the samples. Results show that by increasing food by-products (apple skin powder and grape pomace powder), the colour difference between the control sample and other samples was bigger. The colour of the sample measured by digital image analysis covers the entire sample and is more representative and more objective regarding colour measurement.

Introduction. The aim of the present study is to obtain enriched in vitamin C yoghurt by direct extraction of rosehip fruit in cow's milk. Materials and methods. Cow's milk from cows grown in the Yambol region was used to carry out extraction of rosehip fruits (R. Caniana). The content of vitamin C in the yoghurt obtained was determined by the Officials methods of analysis, 2000, as well as the total number of lactic acid microorganisms contained according to EN ISO 6610:2006; ISO 7889. Results and discussion. The active acidity of the yoghurt was monitored during both periods of preparation and storage. At the end of the storage period (14 days), the active acidity reached pH 4,2-4,3. For the same period, the vitamin C content was the highest in sample 2 and varied from 13,65-13,12 mg.g-2. The dry matter content in the yoghurt obtained was determined. Higher values of dry matter were observed in samples 2 and 3, with values varying from 12,60% to 13,4%. The higher values of the dry matter content in the product were due to the pectin type substances extracted during the extraction process. The pectin substances extracted into the milk stabilized the coagulum, improved the taste and the nutritious value of the yoghurt obtained. The total number of viable bacteria in the yoghurts obtained was determined and they were found to increase during the storage period. The highest total number of viable lactic acid bacteria was observed for Sample 2-3,6.10 8 CFU.g-2 which is about 10 times more than these in Sample 1 (reference). Conclusions. The yoghurt obtained by direct extraction of dry rosehip fruits (Rosa canina L) into cow's milk at hydromodule 1:15 possessed the properties of functional food because of the content of vitamin C in it which varied from 13,65 to 13,12 mg.g-2. The preparation of vitamin C enriched yoghurt can be used to produce new lactic acid products providing health benefits.

Rosehip fruits are an abundant source of bioactive compounds with enormous application in food technology, because of its nutritional and healthy properties. However, isolation and characterization of rosehip pectin remained challenges, because its properties depend on extraction procedure. Therefore, this study aims to evaluate the characteristics of ammonium oxalate-extracted rosehip pectin and its rheological behavior. Dried rosehip fruits (cultivar Plovdiv 1) were used for alcohol-insoluble solids (AIS) preparation. Rosehip pectin was extracted from AIS using 0.5% aqueous ammonium oxalate. The obtained polysaccharide was characterized with a degree of esterification 68%, degree of acetylation 1.0%, anhydrouronic acid content 87% and yield 13%. FTIR spectrum confirmed the pectin structure with typical bands, especially in finger print region showing the presence of α-(1→4)-bond between the galacturonic acid units. To the best of our knowledge, some physicochemical properties of rosehip pectin were evaluated for the first time. The rheological studies showed the non-Newtonian, shear-thinning and weak thixotropic behavior. The rosehip pectin demonstrated good swelling properties (22 ml/g), higher water holding capacity (6.04 g water/g sample), than oil-holding capacity (2.44 g oil/g sample). The obtained results highlighted that rosehips are rich in pectin with valuable rheological properties, revealing their potential use in food technology.

The aim of the present paper is to establish the influence of sucrose on the basic properties of the cookies – losses during baking, thickness, volume, specific volume, colour, as well as on their texture and sensory characteristics. A total of six kinds of cookies were prepared from wheat four, barley flour and mixture of them in ratio 50:50, in two groups according to the sweetener used – with and without sucrose. The results obtained indicated that sucrose and the barley flour exert certain effect on the basic physical properties of the cookies, as well as on their texture and sensory characteristics. When sucrose is used for preparation of cookies, beside that it imparts sweet taste, the baking losses decreases (13.64 %), thicker cookies are produced (15.95 mm), diameter (68.90 mm), expansion factor (44.43), volume (40 cm3) and specific volume (1.65 cm3/g) compared to the cookies prepared without sucrose. The sucrose containing cookies are harder, darker and have more intense red and yellow colour. It was found from the sensory analysis carried out that these cookies are preferred by the consumers. The addition of barley flour to the cookies composition results in higher loss during the baking but the cookies obtained have bigger diameter compared to these which do not contain barley flour. The cookies prepared from mixture of wheat and barley flour in ratio had the best sensory properties.