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Thirty-three varieties of dairy products were analysed for fat and cholesterol contents, and a high correlation (r=0.983) was found between these two compositional attributes. Cholesterol concentration was independent of processing factors such as heat-treatment of the raw material, use of starter culture, type of the starter organisms employed and whipping or flavouring of the product. The non-fat varieties of fluid, fermented and dried milks showed significantly increased cholesterol-to-fat ratios compared to the other products tested because they contained considerable amounts of small fat globules and, therefore, had a large surface area with cholesterol bound to the fat globule membranes. The results of this study may be useful when establishing dietary guidelines for the general public according to health concerns, when formulating diets for population groups with special requirements or when assessing fat and cholesterol intakes in epidemiological studies aimed at investigating the relationship between diet and health.

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Acta Alimentaria
Authors:
V. Kapcsándi
,
A.J. Kovács
,
M. Neményi
, and
E. Lakatos

The aim of our experiments was to demonstrate the non-thermal effect of microwave treatment on Saccharomyces cerevisiae fermentation activity. A method was developed for studying the effects of various treatments in the course of must fermentation. The raw material (must) was treated in different ways: (i) heat transfer; (ii) microwave treatment; (iii) inoculation with yeast, and (iv) their combinations. The results of the treatments were compared with respect to alcohol concentration, sugar content, and acidity. The results proved that sugar content of the treated samples rapidly decreased compared to the control sample, and fermentation time was 40% shorter in the fastest case. These results can be explained by the yeast inoculation and microwave treatment. Due to non-thermal effects, fermentation capacity increased by about 30%, while the energy consumption decreased.

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Efforts have been made to predict the sensory profile of coffee samples by instrumental measurement results. The objective of the work was to evaluate the most important sensory attributes of coffee samples prepared from ground roasted coffee by electronic tongue and by sensory panel. Further aim was to predict the Arabica concentration and the main sensory attributes of the different coffee blends by electronic tongue and to analyze the sensitivity of the electronic tongue to the detection of poor quality coffee samples. Five coffee blends with known Arabica and Robusta concentration ratio, five commercially available coffee blends and a poor quality coffee were analyzed. The electronic tongue distinguished the coffee samples according to the Arabica and Robusta content. The sensory panel was able to discriminate the samples based on global aroma, bitterness and coffee aroma intensity (p < 0.01). The Arabica concentration was predicted from the electronic tongue results by PLS with close correlation and low prediction error. Models were developed to predict sensory attributes of the tested coffee samples from the results obtained by the electronic instrument.

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Acta Alimentaria
Authors:
F. Békés
,
K. Ács
,
Gy. Gell
,
Cs. Lantos
,
A-M. Kovács
,
Zs. Birinyi
, and
J. Pauk

Consumption of “gluten-containing” diet causes disease for a significant minority of people who consume foods derived from wheat, rye, barley, and possibly oat. The fact is, however, that in several types of diseases related to the consumption of “gluten-containing” cereals, the trigger compounds are not components of gluten. The current view of medical experts is that, excluding people suffering from celiac disease, the majority of individuals who are feeling better on the “wheat-free” or “gluten-free” diet could select a food containing much healthier, low level of fermentable oligosaccharides (often called as FODMAP). To satisfy the specific health related demands of certain consumer groups, the challenge is in front of cereal breeding to develop new, “healthier” germplasms, suitable to produce such products by the food industry. This report aims to give an overview of some aspects of recent developments in this booming area, (i) summarizing the up-to-date knowledge on cereals-related health disorders; (ii) reporting on the status of developing celiac-safe cereals, and finally (iii) highlighting the potential of developing “healthier” spelt-based cereal products through the progress in an ongoing spelt breeding program.

Open access
Acta Alimentaria
Authors:
J. Soós
,
Sz. Kozits
,
Z. Kovács
,
E. Várvölgyi
,
D. SzöllőSi
, and
A. Fekete

Nowadays quality measurement is an important topic in food quality control. The electronic tongue (ET) can be a useful tool in this feld. The objective of our work is to demonstrate the application potential of ET for the evaluation of different coffee, wine and carrot juice samples and to compare the results with sensory attributes. ET was able to distinguish the different coffee samples. The Arabica concentration of the samples were predicted with close correlation (R2=0.98) and low error (RMSEP=3.16). The Arabica content of commercial samples were also determined. The ET measurement results of different wine samples showed a tendency similar to the increasing ‘acidic content’ determined by sensory evaluation. The closest correlation between ET and sensory evaluation was found with the ‘acidic taste’ (R2=0.87) and the lowest prediction error was observed with the prediction of ’fruit taste’ (RMSEP=6.11). Carrot juice samples were also distinguished by ET. Sensor SRS, developed for sour taste, gave the highest correlation (r=−0.99) with the sour taste of the carrot juice samples. The conclusion is that ET is a useful instrument in the feld of food quality control when appropriate statistical methods are applied.

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Progress in Agricultural Engineering Sciences
Authors:
V. Parrag
,
Z. Gillay
,
Z. Kovács
,
A. Zitek
,
K. Böhm
,
B. Hinterstoisser
,
R. Krska
,
M. Sulyok
,
J. Felföldi
,
F. Firtha
, and
L. Baranyai

Abstract

One of the most important food safety issues is the detection of mycotoxins, the ubiquitous, natural contaminants in cereals. Hyperspectral imaging (HSI) is a new method in food science, it can be used to predict non-destructively the changes in composition and distribution of compounds. That is why, in the last decade, the potential of HSI has been evaluated in many fields of food science, including mycotoxin research.

The aim of the recent study was to test the feasibility of HSI for the differentiation according to the toxin content of cornmeal samples inoculated with Fusarium graminearum, Fusarium verticillioides and Fusarium culmorum and samples with natural levels of mycotoxins. Samples were measured in the near infrared wavelength range of 900–1,700 nm and mean spectra of selected regions of interest of each image were pre-treated using Savitzky-Golay smoothing and standard normal variate (SNV) method. On the spectra, partial least squares discriminant analysis (PLS-DA) was carried out according to the level of contamination. Partial least squares regression (PLSR) method was used to predict deoxynivalenol (DON) content of samples and the cumulative toxin content: the sum of fumonisins (FB1, FB2) and DON content of samples. Based on the promising results of the study, HSI has the potential to be used as a preliminary testing method for mycotoxin content in feed materials.

Open access
Progress in Agricultural Engineering Sciences
Authors:
K. Szalay
,
B. Keller
,
R. Rák
,
N. Péterfalvi
,
L. Kovács
,
J. Souček
,
F. Sillinger
, and
A. Jung

Abstract

One of the biggest challenges of raspberry production in Hungary nowadays is reducing the unfavorable effects of climate change. The maturation phase of main varieties within this region falls in a period of extremely high temperature and atmospheric drought detaining desirable fruit growth. Dedicated plant breeding alone is not enough. An immediate action is required. There has been a need for physical protection against excessive direct radiation. In order to restore, or even save the domestic raspberry production and market, introducing of greenhouse or polytunnel solutions are needed. Experimental plantations of three different raspberry varieties were set in two repetitions: covered and uncovered versions. Each cover has characteristic interaction with light which can generate different environmental conditions and also differences in plant growth and fruit quality. Besides the monitoring of elementary biological indicators, a wide range of sensors (temperature, humidity, solar irradiation) was used to identify differences and to find the optimal tunnel material for maximal plant productivity. Within the framework of the project we also tested a portable spectroradiometer and a snapshot imaging camera to study the practical value of proximal sensing in water- and photosynthetic light use efficiency and vitality mapping.

Open access