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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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Contents
18.10.2014.
Original scientific paper
Effect of pre-treatments on solar drying kinetics of red seedless grapes (cv. Monukka)
Two different pre-treatments were applied to grapes prior to drying in a mixed mode solar dryer. Grapes were blanched in water and in a 0.1% sunflower oil water emulsion, both at 99◦C and for approximately 15 seconds. Several models were tested to fit the experimental data of drying curves but the normalized Newton model gave the best fit results. Samples blanched in hot water or in the 0.1% edible oil emulsion had faster drying rates than untreated samples. Contrary to what was expected, pre-treating with the 0.1% edible oil emulsion did not increase the drying rate to a higher extent than blanching. Pre-treatments did not give a noteworthy difference in the total drying time. However, they had an important role in accelerating initial drying rates, thus preventing moulds and bacterial growth and consequently increasing farmers’ income
Ines N. Ramos, Teresa R.S. Brandao, Cristina L.M. Silva
18.04.2014.
Original scientific paper
Dried Fruit Matrices Incorporated with a Probiotic Strain of Lactobacillus plantarum
The development of fruits and vegetables containing probiotics is a topic of great interest and popularity for health-conscious consumers. The aim of this study was to evaluate the possibility of using dried fruit matrices as delivery vehicles for probiotics. Different fruits — kiwi, mango, strawberry, pineapple, banana — were used as food matrices to test the viability of a strain of Lactobacillus plantarum, which was determined after drying at 40ºC and at different storage times. Cell survival after drying decreased by ca. 1 log in banana and strawberry, to 3 log, for kiwi. The bacterial numbers in banana and strawberry dried pieces at the time of storage at room temperature and 4ºC were approximately 107 cfu/g. After 37 days storage at room temperature, no viable counts were observed in any of the fruits studied. However, at 4ºC after this period of time, viable cells were detected for all the fruits (1.9x106 cfu/g, 1.5x105 cfu/g 1.5x105 cfu/g, 4.7x104 cfu/g 8.0x103 cfu/g, for strawberry, banana, kiwi, mango and pineapple, respectively).
Catarina Ribeiro, Ricardo Freixo, Joana Silva, Paul Gibbs, Alcina Morais, Paula Teixeira
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
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
01.12.2012.
Professional paper
Mechanical properties of rough and dehulled rice during drying
Osvaldo Resende, Paulo César Corrêa, Gabriel Henrique Horta de Oliveira, André Luis Duarte Goneli, Carmen Jarén
01.12.2012.
Professional paper
Viability of the microencapsulation of a casein hydrolysate in lipid microparticles of cupuacu butter and stearic acid
Samantha Cristina Pinho, Janaina Costa Da Silva
01.12.2012.
Professional paper
Physical properties of honeys produced in the Northeast of Brazil
Patricia Argemira Costa, Izabel Cristina Freitas Moraes, Ana Mônica Q.B. Bittante, Paulo José do Amaral Sobral, Catarina A. Gomide, Celso C. Carrer
01.12.2012.
Professional paper
Effect of drying techniques on the retention of antioxidant activities of Saskatoon berries
Pranabendu Mitra, Venkatesh Meda, Rick Green