Jelena Krulj

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.

Extraction methods of Amaranthus sp. grain oil isolation

BACKGROUND Amaranthus sp. is a fast-growing crop with well-known beneficial nutritional values (rich in protein, fat, dietary fiber, ash, and minerals, especially calcium and sodium, and containing a higher amount of lysine than conventional cereals). Amaranthus sp. is an underexploited plant source of squalene, a compound of high importance in the food, cosmetic and pharmaceutical industries. RESULTS This paper has examined the effects of the different extraction methods (Soxhlet, supercritical fluid and accelerated solvent extraction) on the oil and squalene yield of three genotypes of Amaranthus sp. grain. The highest yield of the extracted oil (78.1 g kg(-1) ) and squalene (4.7 g kg(-1) ) in grain was obtained by accelerated solvent extraction (ASE) in genotype 16. Post hoc Tukeys HSD test at 95% confidence limit showed significant differences between observed samples. Principal component analysis (PCA) and cluster analysis (CA) were used for assessing the effect of different genotypes and extraction methods on oil and squalene yield, and also the fatty acid composition profile. Using coupled PCA and CA of observed samples, possible directions for improving the quality of product can be realized. CONCLUSION The results of this study indicate that it is very important to choose both the right genotype and the right method of extraction for optimal oil and squalene yield.

The betaine content in common cereal-based and gluten-free food from local origin

In this study, betaine content in cereal grains, cereal-based products, gluten-free grains and products of mainly local origin was surveyed. Estimates of betaine are currently a topic of considerable interest. The principal physiologic role of betaine is as an osmolyte and methyl donor. Inadequate dietary intake of methyl groups causes hypomethylation in many metabolic pathways which leads to alterations in liver metabolism and consequently, may contribute to numerous diseases such as coronary, cerebral, hepatic and vascular. Cereals are the main sources of betaine in human diet. Results showed that betaine content in grains is variable. Spelt grain was found to be a richer source of betaine (1848 g/g DM) than that of common wheat (532 g/g DM). Gluten-free ingredients and products were mainly low in betaine (<150 g/g DM). Amaranth grain is a remarkable gluten-free source of betaine (5215 g/g DM). Beet molasses is an ingredient which may increase betaine content in both cereal-based and gluten-free products.

Betaine in Cereal Grains and Grain-Based Products

Betaine is a non-essential nutrient which performs several important physiological functions in organisms. Abundant data exist to suggest that betaine has a potential for prevention of chronic diseases and that its dietary intake may contribute to overall health enhancement. Several studies have pointed out that the betaine status of the general population is inadequate and have suggested nutritional strategies to improve dietary intake of betaine. Cereal-based food has been implicated as the major source of betaine in the Western diet. This review summarizes the results on the betaine content in various cereals and related products. Attention has been given to the betaine content in gluten-free grains and products. It also discusses the stability of betaine during processing (cooking, baking, extrusion) and possibilities to increase betaine content by fortification.

Mycobiota on common wheat ( Triticum aestivum) and spelt (Triticum aestivum ssp. spelta) grains from the region of Vojvodina in 2015

The incidence of mycobiota on common wheat (Triticum aestivum) and spelt (Triticum aestivum ssp. spelta) samples, collected during the harvest in 2015, was investigated. The obtained results showed that more genera of mycobiota were isolated from the common wheat grains than from the spelt grains. The most frequently isolated species from common wheat grains belonged to genus Alternaria (41.7%), followed by Fusarium (15.2%), while the incidence of this mycobiota on the spelt grains were 32.4% and 10.4%, respectively. Aspergillus flavus was identified in 40.0% wheat samples, with the incidence of 2.0%. Additionally, this study was undertaken in respect of the occurrence and toxigenic potential of A. flavus isolates from these small grain cereals. A simple screening method was applied to determine toxigenic profiles (aflatoxins production) of A. flavus isolates from common wheat. The results revealed the importance of precise investigation of mycobiota distribution on common wheat and spelt grains, and especially the investigation of toxigenic potential of A. flavus.

Occurrence of aflatoxin B1 in Triticum species inoculated with Aspergillus flavus

Effects of climate change, global trade and technological changes in processing industries cause higher occurrence of Aspergillus flavus and aflatoxin B1 (AFB1) in cereal crops. Four Triticum species: common wheat (Triticum aestivum L.), spelt (T. aestivum ssp. spelta L.), Khorasan wheat (Triticum turgidum ssp. turanicum Jakubz.) and hybrid wheat (T. aestivum L.– F1) were examined for their response to A. flavus infection and production of AFB1. The grains were obtained from control and artificially field inoculated wheat with A. flavus isolates (No. 1 and No. 2) in the 2016 vegetation season in the region of Vojvodina (Northern province of Serbia). Spelt wheat showed the strongest response to the infection in comparison to other analysed wheat species due to specific physico-chemical characteristics of the hull. The weakest response to A. flavus infections was noted in Khorasan wheat. The highest AFB1 level (256 μg/kg) was observed in the dehulled spelt grains, in comparison to other species where the AF...

The influence of plant protein on the properties of dough and the quality of wholemeal spelt bread

The paper presents the effect of a soy protein concentrate (protein content 65%) as a substituent (substituting 20% wholegrain spelt flour) and a pea protein isolate (protein concentration 90%) as a substituent (substituting 5% and 10% wholegrain spelt flour) on the rheological characteristics of spelt dough and on the physical and sensory characteristics of spelt bread enriched with proteins. The stability of dough supplemented with a soy protein concentrate has turned out to be higher than the stability of dough supplemented with pea protein isolates. It is probably the result of different protein behaviour in soybeans and peas. The applied ingredients have manifested different effects on the specific bread volume. In comparison to the control bread, the specific volume of bread samples have been reduced significantly with addition of a 20% soy protein concentrate and a 10% pea protein isolate (from 1.83 ml/g to 1.39 and 1.38 respectively). On the other hand, addition of a 5% pea protein isolate has not brought to a significant decline in the specific bread volume. Addition of a 10% pea protein isolate has increased the chewiness while this parameter has not changed significantly in relation to the control bread with addition of 5% pea protein and 20% soy protein. Spelt bread with 5% pea isolated protein is the most acceptable according to the overall sensory acceptance among all the analysed samples.

A possibility of determining the authenticity of organic wheat using GC-MS

Qualitative analysis of liposoluble wheat extract from conventional, integrated, organic, biodynamic and control farming systems was performed by gas chromatography with mass spectrometry (GC-MS). Organic and biodynamic farming systems were close to each other versus conventional and integrated which are similar in fertilization and plant protection. In the control treatment no fertilization or plant protection was used. Cluster analysis (CA) was applied to classify the samples according to lipid profiles in wheat from different farming systems. The obtained results showed that better discrimination of wheat samples was achieved by analyzing the peak area after 18 min retention time (non-saponifiable lipid fraction), than used the peak area for the whole chromatogram. The study has found that this method can be a potentially used for making a distinction between organic and non-organic wheat production.

The development and validation of HPLC method for quantification of DL-α-tocopherol in quinoa seeds (Chenopodium quinoa willd.)

Aiming to achieve a precise method with easy application, this study presents the development and validation of a fast method for quantification of vitamin DL-α-tocopherol in quinoa seeds. The methodology was based on an extraction procedure using ultrasonic bath and determination by normal-phase HPLC with UV-VIS detector. Validation parameters showed adequate linearity, relative standard deviations between 0.5 and 0.8% (n=10), limits of detection and quantification were 3.0 ng/mL and 11.0 ng/mL, respectively. Moreover, testing the robustness of the method suggested that it was not changeable with time or condition. The results showed that this method is accurate and simple and thus applicable in laboratories for determination of DL-α-tocopherol in quinoa seeds.