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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

Effect of Biopreservatives on Storage Life of Papaya (Carica papaya L.)

In this experiment the effect on post-harvest preservation of papaya (Carica papaya L.) fruit coated with either Aloe gel (AG; 100%) or papaya leaf extract with Aloe gel (PLEAG; 1:1) was studied. To evaluate the role of coating on ripening behavior and quality of papaya the uncoated and coated fruits were stored and ripened at room temperature (25 °C-29 °C) and 82-84% relative humidity. Physico-chemical properties were analyzed at 4 day intervals during the storage period. The incidence of disease attack was also visually observed. The overall results showed the superiority of AG and PLEAG coating in lengthening the shelf-life of papaya fruit compared to controls which showed significant decay from 6th day onward and complete decay within 12 days of storage. The AG and PLEAG coated fruits maintained their shelf life for 12 days and decayed at 16th day. The coated fruits also maintained their color, flavor and firmness up to 12 days of storage. An increase in ascorbic acid content (120.2 mg/100 g) was also found in coated fruits in contrast to the control (59 mg/100 g). Only 27% disease incidence was observed in AG and 13% in PLEAG coated fruits as compared to control (100%) during the storage period. The results of this study show that both AG and PLEAG coatings have excellent potential to be used on fresh produce to maintain quality and extend shelf-life.

Fatema Brishti, Jawadul Misir, Ayesha Sarker

18.10.2013.

Original scientific paper

The AgroParisTech “Social Openings” mission

Underprivileged secondary school and college students tend to demonstrate limited ambitions with regards to further education and acquiring superior qualifications. In a partnership with higher education schools, such as AgroParisTech, encounters have been organised between high school students and higher education students acting as volunteering mentors.The aim is to present the high school students with the opportunity to explore new opportunities as well as to provide them with information about high profile careers and higher level training through various activities led by the higher education students, as well as through meetings, visits, weekends organised around a specific theme. Examples of such initiatives  show what benefits both the high school and higher education students can derive from them.

Annie Baroiller, Elisabeth Dumoulin

18.10.2012.

Original scientific paper

Effect of drying techniques on the retention of antioxidant activities of Saskatoon berries

The main objective of this research was to compare the retention of antioxidant activity and total anthocyanin content of Saskatoon berries dried by freeze drying, microwave-vacuum drying, thin layer hot air drying and vacuum drying. Antioxidant activity of berry samples was determined by DPPH radical scavenging and ABTS radical scavenging, and the pH differential method was used to determine total anthocyanin content of the berry samples. The results showed that the freeze dried Saskatoon berries exhibited the highest retention of anthocyanin and antioxidant activity among the dried samples, followed by microwave-vacuum dried berries, thin layer hot air dried berries and vacuum dried berries. There were significant differences between the berry samples at P<0.05.  DPPH radical scavenging and ABTS radical scavenging were correlated linearly with an R2 value of 0.99 at P<0.05 showing their effectiveness for the determination of the antioxidant activity of the Saskatoon berries. However, the DPPH radical scavenging assay was more effective than the ABTS radical scavenging assay. The results also showed that antioxidant activity of the berries was highly correlated with the total anthocyanin content of the fruit. The reduction of anthocyanin in dried berry samples was linearly correlated with the reduction of DPPH radical scavenging with an R2 value of 0.97 at P<0.05 and, also, linearly correlated with the reduction of ABTS radical scavenging with an R2 value of 0.88 at P<0.05.

Pranabendu Mitra, Venkatesh Meda, Rick Green

18.04.2013.

Original scientific paper

The impact of cold chain temperature abuses on the quality of frozen strawberries (Fragaria ×ananassa)

The quality of frozen foods can be negatively affected if improper storage and distribution temperatures are allowed. The objective of this study was to investigate the effect of freeze-thaw cycles, which may occur in the cold chain, on colour (Lab, Total Colour Differences (TCD), chroma and hue angle) and vitamin C (ascorbic and dehydroascorbic acids) content of frozen strawberries (Fragaria ×ananassa, Duschesne, cv. Selva). A plan of temperature abuses (TAs) was established, based on a real situation, and applied to frozen strawberries during a four month frozen storage period. The results showed that the lightness (L) was the only parameter that was not significantly affected by range of TAs studied. The colour showed some variation on the parameters a, b, TCD, chroma and hue angle. During TAs, ascorbic acid decreased about 75% and dehydroascorbic acid increased 73%. The non-abused strawberry samples showed better overall appearance than the abused samples. This work contributes to an understanding of the quality changes of frozen strawberries that might occur during frozen storage and cold chain distribution.

Rui Cruz, Margarida Vieira, Cristina Silva

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

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