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Volume 13, Issue 2, 2024

Online ISSN: 2182-1054

Volume 13 , Issue 2, (2024)

Published: 18.10.2024.

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18.04.2013.

Original scientific paper

Antioxidants, their properties, uses in food products and their legal implications

Oxidation decreases consumer acceptability of food by changing its organoleptic properties, destroying essential nutrients and producing toxic compounds. Antioxidants delay oxidation of lipids in foods as well in human systems. Studies reveal that synthetic antioxidants may trigger diseases in human when consumed over a certain concentration. The toxicological effects of synthetic food antioxidants have been the focus of controversy in recent years. There is scope to use natural antioxidants, present in many components of food and plant sources, as a preservative. In this review different synthetic and natural antioxidants present in various foods, reactions with food and the biological system, extraction techniques and their pitfalls as well as legal implication are discussed.

Indrajit Thorat, Dipali D. Jagtap, Debabandya Mohapatra, D. C. Joshi, R. F. Sutar, S. S. Kapdi

18.04.2013.

Original scientific paper

Physical properties of honeys produced in the Northeast of Brazil

The aim of this work was to study the rheological, thermal and some other physical-chemical properties of selected honeys produced in the Northeast of Brazil. Two samples were produced by native “Jandaira” bees (Melipona subnitida) and ten other samples by Africanized bees (Apis mellifera). The samples were analyzed for pH, water activity (aW), soluble solids and water content. Viscosity flow curves were obtained using a rheometer (25ºC, 0-100s-1). Thermal analyses were performed on a differential scanning calorimeter, with heating rate of 10ºC/min (-100 to 100ºC). The water content and the pH of the honey samples varied from 17.2 to 27.9% and from 3.2 to 4.2, respectively, and, the aW of the samples varied from 0.57 to 0.74. Two samples were out of specification with respect to water content, according to Brazilian laws. In relation to rheology, all honey samples showed Newtonian behaviour with no thixotropy or dilatancy. The viscosity varied as an exponential function of the water content. The highest viscosity was obtained for the sample with lower values of water content and aW. Thermograms showed a glass transition (Tg) occurring between -52.4 and -42.6ºC, in the samples produced by Apis mellifera and -67.6 and -57.0ºC for the other samples. A linear relationship was obtained between Tg and water content. In conclusion, the honey viscosity depended on the water content of the product. The higher the water value and therefore the greater the aw, the lower viscosity and Tg of the samples.

Patricia Argemira Costa, Izabel Moraes, Ana Mônica Q.B. Bittante, Paulo José do Amaral Sobral, Catarina A. Gomide, Celso C. Carrer

18.10.2013.

Original scientific paper

Quality and safety of camel milk along the value chain in Eastern Ethiopia

The safety of camel milk was assessed along the value chain in Erer, eastern Ethiopia. A total of 24 camel milk samples were aseptically collected from producers in Erer (n=12), and wholesalers and retailers (n=12) along the chain. Milk quality parameters were analyzed following standard procedures. The mean (±SD) total bacteria (TBC), Enterobacteriaceae (EC), coliform (CC), spore-forming bacteria (SFBC) and yeast and mould (YMC) counts of the milk samples analyzed were 5.2 ± 1.90, 3.2 ± 2.30, 2.9 ± 2.27, 2.1 ± 2.41 and 2.7 ± 1.61 log10 cfu mL-1, respectively. The TBC, EC, CC and SFBC of milk samples obtained from retailers in the final marketing sites were significantly higher (P < 0.05) than those obtained from producers and wholesalers in Erer. Salmonella spp. was detected in milk samples collected from all sites. Other microorganisms isolated from camel milk samples include Staphylococcus aureus (16.2%), Entrobacter spp. (14.9%), Streptococcus spp. (13.5%),Escherichia coli (8.1%), Acinetobacter spp. (7.4%), Staphylococcus epidermidis (6.8%), Klebsiella spp. (6.1%), Bacillus spp. (5.4%), Corynebacterium spp. (5.4%), Micrococcus spp. (4.7%), Lactobacillus spp. (4.1%), Listeria spp. (4.1%), Pseudomonas spp. (2%) and Shigella spp. (1.4% ). The quality of camel milk produced in the study area was generally poor and microbial contamination of camel milk occurs along the value chain while it is transported from the production site to the market. This calls for strict hygienic measures along the entire value chain in order to improve the quality and safety of camel milk produced in the area evaluated.

Mulugojjam Adugna, Eyassu Seifu, Ameha Kebeded, Reiner Doluschitz

18.10.2013.

Original scientific paper

Effect of structural modifications on the drying kinetics of foods: changes in volume, surface area and product shape

Macro and micro-structural changes take place during food dehydration. Macro-structural changes encompass modifications in shape, area and volume. Studies of such changes are important because dehydration kinetics (essential for calculating industrial dryers) may be highly influenced by changes in food shape and dimensions. The overall changes in volume, surface area (“shrinkage”) and shape (Heywood factor, with provides a close description of food shape) were determined experimentally, and the results were correlated with simple expressions. Hence, although dehydration kinetics can be modeled with simplified overall shrinkage expressions, the possibility of selecting a suitable geometry and predicting the characteristics dimensions will provide higher accuracy. An additional unresolved problem is the lack of a general model that predicts macro-structural changes for various foods and diverse geometries. In this work, based on experimental data of sweet and sour cherries, and rose hip fruits, a simplified general model to predict changes in volume and surface area are proposed. To estimate how the changes in characteristic dimensions affect the kinetic studies, experimental drying curves for the three fruits by means of a diffusional model considered the following variants for the characteristic dimensions: (i) The radius of the fresh food, assumed constant; (ii) The radius of the partially dehydrated product; (iii) The radius predicted by the correlation for structural changes, especially volume, obtained in this work and generalized for the three fruits, and (iv) to demonstrate the need to study the macro-structural changes for all dehydrated foods, also be present the case of a restructured food.

Antonio De Michelis, Carlos A. Márquez, Alejandra Mabellini, Elizabeth Ohaco, Sergio A. Giner

01.12.2012.

Professional paper

National Food Safety Systems in the European Union: A Comparative Survey

This paper is a comparative survey of the National Food Safety Systems (NFSS) of the European Union (EU) Member-States (MS) and the Central EU level. The main organizational structures of the NFSS, their legal frameworks, their responsibilities, their experiences, and challenges relating to food safety are discussed. Growing concerns about food safety have led the EU itself, its MS and non-EU countries, which are EU trade-partners, to review and modify their food safety systems. Our study suggests that the EU and 22 out of 27 Member States (MS) have reorganized their NFSS by establishing a single food safety authority or a similar organization on the national or central level. In addition, the study analyzes different approaches towards the establishment of such agencies. Areas where marked differences in approaches were seen included the division of responsibilities for risk assessment (RA), risk management (RM), and risk communication (RC). We found that in 12 Member States, all three areas of activity (RA, RM, and RC) are kept together, whereas in 10 Member States, risk management is functionally or institutionally separate from risk assessment and risk communication. No single ideal model for others to follow for the organization of a food safety authority was observed; however, revised NFSS, either in EU member states or at the EU central level, may be more effective from the previous arrangements, because they provide central supervision, give priority to food control programs, and maintain comprehensive risk analysis as part of their activities.

Andreas Hadjigeorgiou, Elpidoforos S. Soteriades, Anastasios Philalithis, Anna Psaroulaki, Yiannis Tselentis, Achilleas Gikas

01.12.2012.

Professional paper

Profile of currently employed European Food Scientists and Technologists: Education, experience and skills

The food & drink (F&D) sector in Europe ranks low in innovation and the European F&D industry has been losing importance in the global market. The food professionals, i.e., food scientists and technologists (FSTs), may not be meeting the varied demands of the sector. Here, we identify education, experience and skills of current FSTs and compare  geographic regions and employment areas. Between 2009 and 2012, 287 questionnaires representing over 4000 FSTs were collected from employers in 16 countries. Analyses showed that more than 80% of FSTs have a university degree; but only in Industry in the Central European region are most degrees in food science/technology. More than half of FSTs, and almost 60% in the South, have less than 10 years’ experience. The most common FST job title is Quality Manager, but with several variations based on region and employment area. Among skills, the most common is Communicating; found in over 90% of FSTs in all regions and employment areas. Food Safety is the most common of the food sector-specific skills, present in more than 75% of FSTs, yet there are differences in food sector skills based on employment area. Overall, these data suggest similarities among currently employed food professionals throughout Europe; they are young and highly educated, but also differences, especially in their food sector-specific skills. An understanding of the current FST should contribute to the improvement of FST training and thus benefit the European food sector.

Katherine Flynn, Barbara Ruiz Bejarano, Erik Wahnstrom, Camelia Echim, Mafalda A.C. Quintas

01.12.2012.

Professional paper

Use of response surface methodology to evaluate the reducing power in binary solutions of ascorbic acid with natural polyphenolic antioxidants

Natural polyphenols, ferulic acid (FA) and hesperetin (Hp) were tested for their Fe3+-reducing power, using the TPTZ methodology, as a first step to rank them according to their antioxidant potential. Ranking also included quercetin (Qt), a very well-studied natural, polyphenolic antioxidant, and ascorbic acid (AA). All phenolics considered were also tested in binary mixtures with AA, to illustrate possible mixture effects. By employing a simple linear regression approach, combinations of AA / Qt and AA / Hp were shown to result in antagonistic effects, whereas in mixtures of AA / FA, synergism was observed. To thoroughly investigate the role of the relative concentrations of the antioxidants, a 3×3 factorial design was implemented. This approach enabled the recording of the response (reducing power) upon simultaneous variation of concentrations of both antioxidants in the mixtures, and revealed only antagonism for every combination tested. It is proposed that in similar investigations factorial designs need to be implemented for reliable prediction of the antioxidant response(s) within appropriate limits. This is particularly crucial for antioxidants that are destined to be added in food matrices, where maximal antioxidant protection is always sought.

Marie Aoun, Dimitris P Makris

18.10.2012.

Original scientific paper

Differences in quality parameters between types of commercial tea from Argentina

To determine differences in quality parameters between different types of tea elaborated in Argentina, water extract, crude fibre, caffeine, total polyphenol content, antioxidant activity, sorption isotherms and colour parameters (L, a, b) were determined. Fifty-one industrial samples of commercially available teas including green tea, semifermented tea, black tea and black tea sub-product (BTSP) were used for this study.Water extract contents were significantly higher in black tea and green tea (40.3% and 40.7% w/w, respectively), while semifermented tea and BTSP showed higher levels of crude fibre (22.3% and 20.4% w/w, respectively). Caffeine contents of black teas (2.7% w/w) were significantly higher than in the other types of tea. Green teas revealed the highest concentrations of phenolic compounds and the major antioxidant activities (14.9 g GAE/100g dm and 30.0 g AAE/100g dm, respectively). The results also highlighted significant differences (p<0.05) in colour values between the different types of tea.

Ana Thea, María Antonia Lloret, Luis Alberto Brumovsky, Miguel Eduardo Schmalko

01.12.2011.

Professional paper

Evaluation of test-kits for the detection of Escherichia coli O157 in raw meats and cattle faeces.

Escherichia coli O157 detection limits in artificially contaminated beef and cattle faeces samples were determined using Dynabeads anti E. coli O157 immunomagnetic beads, VIDAS-UP, VIDAS-ICE, and real-time PCR (GeneDisc and LightCycler) systems. Dynabeads anti-E. coli O157 immunomagnetic separation (IMS) and the GeneDisc cycler were the most sensitive methods, and could detect an initial 1 CFU in 25g beef samples after 6h of incubation in modified tryptone soya broth with novobiocin (mTSB+n) or buffered peptone water (BPW). The VIDAS-UP method could detect an initial 10 CFU, while VIDAS-ICE and the LightCycler methods could only detect an initial 100 CFU. Higher detection rates were achieved with 18 hour incubations, where an initial 1 CFU in a 25g sample could be detected with all five methods. For cattle faeces enrichments, Dynabeads anti-E. coli O157 IMS could detect an initial 1 CFU after a 6 h incubation in mTSB+n, while the VIDAS-UP and VIDAS-ICE methods could detect an initial 10 CFU and both PCR methods could only detect an initial 100 CFU. Detection rates were lower in BPW, compared to mTSB+n, with thresholds of 100 CFU for VIDAS-ICE, VIDAS-UP and GeneDisc methods, and >100 CFU for the LightCycler method.

Hilda Nyati, Annet Heuvelink, Caroliene Van Heerwaarden, Ans Zwartkruis

01.12.2011.

Professional paper

Challenges and Opportunities for the community of Food Sciences to contribute Towards a Society of Healthier Consumers and a Better World

Despite the tremendous scientific and technological achievements in the production of food, human well-being has not been served to a satisfactory extent. Millions of people are literally killing themselves by excessive eating or wrong use of food, leading to obesity and nutrition-related diseases. At the same time millions of people continue to suffer from lack of food, leading to starvation, malnutrition and death, often before reaching adult age. Parallel to striving for better-safer-healthier food, the community of Food Sciences is faced with the challenge to help educate the average consumer on how to select, handle, store and use food for safe and healthy eating. The need to reshape and reform public education to better serve this task is obvious. What is also obvious is the need for medical professionals to recognize healthy eating (and exercise) as the most valuable tool in preventive medical care. This perspective will concentrate on challenges and opportunities for Food Scientists/Engineers: to contribute towards a society of well-informed, self-protected, active and considerate citizens; to support public (food-related) education and actively participate in the fight against obesity and nutrition-related diseases; to intervene in decision making bodies and underline the importance of education on nutrition and food; to invent avenues and possibilities to contribute to the fight against world hunger; and all in all, to contribute towards a healthier world, a world that will not be split between hunger and obesity.

Harris N. Lazarides

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