Nataša Nedeljković

Aflatoxins contamination of maize in Serbia: The impact of weather conditions in 2015

ABSTRACT In recent years climate changes recorded in temperate regions of Europe have led to aflatoxin (AF) contamination of maize. Thus, the aim of this study was to investigate the influence of weather conditions on levels of aflatoxin B1 (AFB1), aflatoxin B2 (AFB2), aflatoxin G1 (AFG1) and aflatoxin G2 (AFG2) in 180 maize samples collected from the main maize-growing regions (Western Bačka, North Banat, South Banat and Central Serbia) in Serbia after harvest in 2015. The concentrations of AFs were determined by a validated HPLC method with post-column derivatisation and fluorescence detection (HPLC-FLD). The presence of AFB1, AFB2, AFG1 and AFG2 was detected in 57.2%, 13.9%, 5.6% and 2.8% of maize samples in the concentration ranges of 1.3–88.8 µg kg–1, 0.60–2.8 µg kg–1, 1.8–28.5 µg kg–1 and 2.1–7.5 µg kg–1 respectively. The recorded smaller amount of precipitation and especially higher air temperatures during the summer of 2015 were favourable for AF production, which resulted in 32.2% and 21.1% of samples being unsuitable for human consumption, since AFB1 and the sum of AFs concentrations were above 5.0 and 10.0 µg kg–1 respectively. Furthermore, the findings in this study indicate that the microclimate conditions in the investigated regions had a great influence on the contamination frequency of maize with AFs. The highest percentage of samples unsuitable for human consumption, considering both AFB1 and total AFs content were 72.5% and 51.5% respectively from Central Serbia, whilst the lowest percentages of 15.6% and 6.2% respectively were found in Western Bačka. These findings confirmed that maize should be continuously monitored in order to protect human and animal health from the harmful effects caused by AFs contamination.

Relationship of Physicochemical Characteristics with Sensory Profile of Cookies Enriched with Medicinal Herbs

In this work, a range of model cookies enriched with different quantities of medicinal herbs, applied in two forms (pulverized mixture and extract), were studied to compare and describe relationships between physicochemical and sensory data. Multivariate statistical methods were applied to estimate relationships in the analyzed data. Analysis of variance showed that the majority of analyzed parameters were highly significant in discriminating among the samples (p < 0.05), which supported the usefulness of their application in characterizing the quality profile of enriched cookies. Principal component analysis on physicochemical data revealed that cookies at the same enrichment level showed more similarities. Principal component analysis on sensory data exhibited a larger separation between the samples with increasing enrichment levels, especially in the case of pulverized herbal mixture. According to partial least squares regression, two significant partial least squares components explained 92.7% and predicted 78.0% variation in the data. The most important parameters in discriminating between the cookies enriched with medicinal herbs were lightness, red tonality, and hardness. The selected physicochemical parameters could be used in future studies to evaluate variously enriched cookies by establishing models and investigating the predictability of sensory quality.

Antibacterial activity of domestic Balkan donkey milk toward Listeria monocytogenes and Staphylococcus aureus

The aim of this study was to investigate the antibacterial activity of raw milk from Domestic Balkan donkey breed toward Listeria monocytogenes and Staphylococcus aureus. Examination of antibacterial activity was performed in artificially contaminated milk samples by monitoring the changes of count of viable cells of tested bacteria during 8 hours of incubation at 38°C. Lysozyme and fatty acids contents were also determined in donkey milk. The obtained results indicated inhibitory effect of donkey milk toward both tested bacteria. The lysozyme content in the analyzed milk samples was ranged from 0.67 to 3.54 g/L. The most abundant fatty acids with known antibacterial activity toward Gram positive bacteria were linoleic, lauric and oleic acid.

Physicochemical properties and mineral content of honey samples from Vojvodina (Republic of Serbia)

Forty-five honey samples of three honey types - two monofloral (acacia and sunflower) and one polyfloral (meadow) were collected from the Autonomous Province of Vojvodina (Republic of Serbia) and analysed for their physicochemical parameters (moisture, acidity, pH, ash, electrical conductivity, glucose, fructose, hydroxymethylfurfural (HMF), CIE L∗a∗b∗ colour and mineral content). All tested physicochemical parameters were in agreement with the EU regulation except for moisture (4 samples) and HMF content (1 sample). Principal component analysis (PCA) was used for assessing the effects of three honey types on all investigated physicochemical parameters. According to PCA, acacia honey samples can be clearly isolated and form a cluster, while, regarding other honey types, PCA can offer the possibility to distinguish sunflower and meadow honey samples regarding examined physicochemical parameters and mineral content.

Soy Bran Separation Process for Application of Product in the Food Industry

Change of lifestyle, also as contemporary dietary habits of people, requires innovations in the food processing technology and implementation of new ingredients. Fat replacers are well known as ingredients which has been used in the production of low energy products. Furthermore, in the combination with sugar substitutes it is possible to obtain serious energy reduction, while the sensorial properties remains unaffected. A certain lightweight fractions of soy bran separation and milling process could be applied as fat replacers in the food industry, especially in cookie production. Soy bran milled fractions with dietary fibers content (cellulose, hemicellulose, lignin, inulin, pentosans etc.) have been selected for this work. Technological process of soy bran separation and milling starts with a cleaning of the external part of the soy grain, further it is necessary to adjust the moisture content for the efficient mechanical grinding process. New age milling and separation equipment (air separator, cascade classifier, dryer, hammer mill, roller mill) was used for the purposes of experiment. Results obtained with the analyze of microbiological and chemical properties of soy products, along with a probe sieving analysis, indicates a strong potential for use as fat substitutes in bakery, cookie and confectionery production.

Buckwheat-enriched wheat bread: National market placement possibilities

Quality parameters and the possibility of successful placement of buckwheat-enriched wheat bread on the national market are presented in this paper. Analysis of the market position of buckwheat-enriched wheat bread includes demands, offer and competition. Elements that affect the overall retail price of buckwheat-enriched wheat bread are given in details, along with SWOT analysis and marketing plan including target market, market supply and product marketing mix. According to all performed analyses it could be concluded that this product should be positioned on the national market, especially for people with special needs and requirements.