Tag Archives: ascorbic acid

1728-1741 D. Kļava, S. Kampuse, L. Tomsone, T. Kince and L. Ozola
Effect of drying technologies on bioactive compounds maintenance in pumpkin by-products
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Effect of drying technologies on bioactive compounds maintenance in pumpkin by-products

D. Kļava, S. Kampuse*, L. Tomsone, T. Kince and L. Ozola

Latvia University of Life Sciences and Technologies, Faculty of Food Technology, Riga street 22, LV-3004 Jelgava, Latvia
*Correspondence: skampuse@inbox.lv

Abstract:

During the pumpkin processing large amounts of waste material as a combination of pumpkin peel, seeds and the flesh between seeds has produced. Therefore it is important to investigate the possibilities for using the pumpkin residues. The aim of this research was to investigate the effect of different drying technologies on maintenance of bioactive compounds in pumpkin by-products. Two pumpkin residue products of Hubard group pumpkins were used to obtain pumpkin powder: residue products formed in the process of extracting industrial pumpkin purée by heating it in a heat exchanger and treating through a sieve of pulpier; residues resulting from pumpkin juice extraction process mechanically pressed from fresh, chopped pumpkins. In order to be able to choose the most suitable drying technology pumpkin by-products were dried in the microwave-vacuum, convective (at 40, 50, 70 and 80 °C) and freeze-drying type dryers. For all samples total carotenes, the ascorbic acid, total phenols content (TPC) and antiradical activity (DPPH˙, ABTS˙+) were determined by using standard methods. The highest total carotenes content was retained in freeze-dried pumpkin powders. The most suitable drying method for obtaining pumpkin powder with the highest ascorbic acid, total phenolic content and antiradical activity is drying in convective type drying at 80 °C temperature.

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1315–1327 S. Kampuse, L. Tomsone, Z. Krūma, M. Šabovics and I. Skrabule
Effect of lovage phenolics to formation of acrylamide in French fries
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Effect of lovage phenolics to formation of acrylamide in French fries

S. Kampuse¹*, L. Tomsone¹, Z. Krūma¹, M. Šabovics¹ and I. Skrabule²

¹Latvia University of Agriculture, Department of Food Technology, St. Rigas 22, LV-3004 Jelgava, Latvia
²Institute of Agricultural Resources and Economics, St. Zinatnes 2, LV-4126 Priekuli, Latvia
*Correspondence: skampuse@inbox.lv

Abstract:

 One of the novel methods for reduction of acrylamide in food is application of plant phenolics in technological process of Latvian plants as lovage contain significant amounts of plant phenolics and other natural antioxidants. The aim of current research was to determine the effect of lovage extracts to the formation of acrylamide in French fries. Variety ’Lenora’ potatoes were used. Potatoes were sliced and blanched in hot water (85 ± 2 °C 8 min). After blanching samples were treated with lovage water and ethanol extracts and four samples were obtained: control (without additional treatment); SW – sprayed with water extract, IMW – immersed in water extract, SE sprayed with ethanol extract. After treatment all samples were fried in oil (180 ± 2 °C) for 7 minutes. Total phenolic (TPC), vitamin C content and antioxidant activity (DPPH and ABTS) were determined for all samples before and after frying. For fried potatoes acrylamide and breaking force with texture analyser were determined. TPC of samples during frying decreased significantly but comparing fried samples the highest TPC in SE sample was determined. The highest DPPH radical scavenging activity was observed in samples treated with water extract but during frying the DPPH activity for all treated samples was lower than to control sample. The most significant changes in ABTS radical scavenging activity were observed and also the highest activity of sample SE was observed. Vitamin C content decreased significantly during frying, the highest vitamin C content in SE sample was determined. The highest maximal breaking force of fried potatoes was detected for sample IMW, but the lowest for sample SE. The lowest acrylamide content was found in sample, which was sprayed with lovage-water extract.

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31–36 M. Jalakas, K. Kelt and K. Karp
The yield and fruit quality of sea buckthorn (Hippophae rhamnoides L.) after rejuvenation cutting
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The yield and fruit quality of sea buckthorn (Hippophae rhamnoides L.) after rejuvenation cutting

M. Jalakas¹, K. Kelt² and K. Karp¹

¹Institute of Horticulture, Estonian Agricultural University, Kreutzwaldi 64, 51014 Tartu, Estonia; e-mail: kkarp@eau.ee
²Polli Horticultural Institute of the Estonian Agricultural University, 69104 Karksi-Nuia, Estonia; e-mail: asta@pai.neti.ee

Abstract:

The yield and fruit quality of 6 sea buckthorn (Hippophae rhamnoides L.) cultivars of a Moscow breeding programme were studied at the Rõhu Experimental Station in South Estonia. The chemical contents of fruits of sea buckthorn were analysed after 3 months of cold-storage at –18°C. ‘Trofimovskaya’ appeared to have more sugars (2.9%) than the other cultivars. ‘Otradnaya’ had the lowest acid content (2.1%). ‘Vorobjevskaya’, ‘Trofimovskaya’ and ‘Otradnaya’ had higher ascorbic acid contents (about 65 mg/100 g) than the other tested cultivars. ‘Vorobjevskaya’ gave the highest yield (9.6 kg/tree) in the 3rd year after cutting down the trees to 2.5 m height. In the following year, the yield of the experiment was significantly higher, whereas cultivars Trofimovskaya and Botanicheskaya had the biggest yields.

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