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Volume 14, Issue 1, 2025

Online ISSN: 2182-1054

Volume 14 , Issue 1, (2025)

Published: 31.07.2025.

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18.10.2012.

Original scientific paper

Drying kinetics and quality aspects during heat pump drying of onion (Allium cepa L.)

A prototype heat pump dryer has been developed for drying of fruits and vegetables at low temperature and relative humidity to maintain the quality of dried product. Onions, of Nasik red variety were peeled, trimmed and sliced to 2 mm thickness. The onion slices were dried in the heat pump dryer at 35ºC (32 % R.H.), 40ºC (26 % R.H.), 45ºC (19 % R.H.) and 50ºC (15 % R.H.). Samples were also dried in a hot air dryer at 50ºC (52 % R.H.) for comparison. The drying rate increased with increase in drying air temperature, associated with reduced R.H., in the heat pump dryer. Drying took place mainly under the falling rate period. The Page equation, resulting in a higher coefficient of determination and lower root mean square error, better described the thin-layer drying of onion slices than the Henderson and Pabis equation. Heat pump drying took less drying time of 360 min and yielded better quality dried product, with higher retention of ascorbic acid and pyruvic acid and lower colour change, as compared to a hot air dryer at the same drying air temperature of 50ºC.

Nihar Sahoo, Uma Sankar Pal, Sanjaya Kumar Dash, M.D. K. Khan

18.10.2012.

Original scientific paper

Bridging academic research and agribusiness in the recovery of byproducts from swine farming

Nowadays, food production has the challenging mission to encourage the growth of the rural economy assuring long term sustainability of their natural resources. The qualification of human resources and the generation of new knowledge are the main pillars that give sustainability to agribusiness. Animal protein production is one of the branches of the agribusiness sector. Swine production is recognized as an activity of high pollution potential, producing a large quantity of waste. This study aimed to identify the activities developed in partnership among academic, research and extension institutes in a midsize company of the agribusiness sector, more specifically a swine farm (São Roque Farm) in its sustainable restructuring. An exploratory and quantitative research was developed, which comprehended literature reviews, data collection and analysis of documents from the São Roque Farm. It was considered the period that includes the beginning of the sustainable restructuring of the property (2003) until December 2011. During the analysis of the Sustainable Restructuring Project, special attention was given to the readjustment of the wastewater treatment system and to the energy management and carbon credits, being innovative and pilot projects in the state of Santa Catarina. For this purpose, technologies and knowledge are being developed and applied in treatment of three routes: gaseous, liquid and solid. This pilot project allowed the development of applied studies at undergraduate, masters and PhD level and the main results achieved are the improvement of understanding and the achievement of technical and financial benefits by connecting agribusiness, academia and government research institutions.

Estela Nunes, Simone Perazzoli, Janaina Camile Pasqual

01.12.2011.

Professional paper

Determination of Phenolic Compounds in Wines

Wine contains natural antioxidants such as phenolic compounds also known as bioactive compounds. Samples of commercially available Greek wines were analyzed in order to determine this phenolic content. For the analysis, Reversed Phase-High Performance Liquid Chromatography (RP-HPLC) coupled with a multiwavelength Ultraviolet/visible (UV/vis) detector was used. The most abundant phenolic substances detected were (+)-catechin (13.5-72.4 mg L-1 ), gallic acid (0.40-99.47 mg L-1) and caffeic acid (0.87-33.48 mg L-1). The principal component analysis (PCA) technique was used to study differentiation among wines according to their production area. Red wines contained more phenolic substances than white ones. Differences of the phenolic composition in wines of the same cultivar were investigated too.

Charalampos Proestos, Athanasios Bakogiannis, Michael Komaitis

01.12.2011.

Professional paper

Treatment of Olive Mill Wastewater and the Use of Polyphenols Obtained After Treatment

Olive mill wastes are signicant environmental problem especially in Mediterranean areas where they are generated in huge quantities in a short period of time. They are phytotoxic materials because of their high phenol, lipid and organic acid concentrations, but these wastes also contain valuable resources that could be recycled such as a large proportion of organic matter and a wide range of nutrients. The effluent from olive oil mills contains a large amount of polyphenols that have antioxidant properties. The market value of these antioxidants is high and they are commonly used in the food, cosmetics, pharmaceutics and chemical industries. For the management of olive mill wastewater (OMW) and other olive residues, various treatment methods can be used. Many scientists work on more efficient and cheaper treatment alternatives. Due to the great variety of compounds in the waste, several technologies to remove the harmful compounds for the environment should be used single or together. Some of the most used OMW treatments are drying / evaporation, forced evaporation, thermal treatment, centrifugation-ultraltration, electrocoagulation, composting, lagooning, adsorption, powdered activated carbon, filtration, sand filtration, membrane filtration, ultrafiltration, precipitation / flocculation, distillation, electrolysis, co-composting, advanced oxidation processes (AOPs) such as ozonation, hydrogen peroxide / ferrous iron oxidation (the so-called Fentons reagent). Several OMW treatment technologies have been developed aiming at the removal of the main toxic organic compounds. A lot of factors must be considered to choose the treatment methods among them the investment, required area, specic training of the workers, noise and odour emissions and seasonality of production.

Semih Otles, Ilknur Selek

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