Use of a spouted bed to improve the storage stability of wheat germ followed in paper and polyethlyene packages

Stabilization of wheat germ by heating in a spouted bed for 180–540 s with air at 140–200 °C was studied. The lipase activity decreased by 6–65%. Wheat germ processed at 200 °C for 360 s was ranked highest in sensory evaluation, described as having ‘a golden color’ and ‘nutty flavor’, and its lipoxygenase activity had decreased by 91.2%. This product and raw wheat germ were stored in paper, polyethylene and vacuum‐packed polyethylene pouches at 5 °C, room temperature (18–26 °C) and 40 °C, and the moisture contents, water activities, free fatty acid contents and peroxide values were followed for 20 weeks. The increases were faster in paper pouches than in the polyethylene ones; vacuum packaging in polyethylene did not bring about significant improvement. The peroxide values of raw samples exceeded 10 meq O2 kg−1 oil after 3–23 days while those of the processed samples stored at room temperature or 5 °C were still less than 10 after 20 weeks. The free fatty acid content and peroxide value changes were expressed by zero order kinetics, resulting in similar activation energies for the raw and processed samples.
Journal of the Science of Food and Agriculture


Usage of enzymes in a novel baking process
Keskin, SO; Şümnü, Servet Gülüm; Şahin, Serpil (Wiley, 2004-04-01)
In this study, the effects of different enzymes (a-amylase, xylanase, lipase, protease) on quality of breads baked in different ovens (microwave, halogen lamp-microwave combination and conventional oven) were investigated. It was also aimed to reduce the quality problems of breads baked in microwave ovens with the usage of enzymes. As a control, bread dough containing no enzyme was used. Specific volume, firmness and color of the breads were measured as quality parameters. All of the enzymes were found to b...
ULGEN, N; OZILGEN, M (Wiley, 1991-01-01)
The thermal degradation kinetics of ascorbic acid and the inactivation kinetics of pectinesterase were studied experimentally with pH-adjusted orange juice. No simple trends were observed in variation of the kinetic parameters with pH, but both kinetic functions agreed with kinetic compensation relations. An isokinetic temperature was observed for ascorbic acid degradation at pH 2.5, 3.0, and 3.5 implying that the same degradation mechanism was valid at these pH values. A large deviation at pH 4.0 from t...
Usage of spouted bed and microwave assisted spouted bed dryers in bulgur production
Kahyaoğlu, Leyla Nesrin; Şahin, Serpil; Department of Food Engineering (2009)
The main objective of this study was to investigate the effect of spouted bed and microwave assisted spouted bed drying on drying rates and quality parameters of bulgur. The drying experiments were performed at three air temperatures (50, 70, 90oC) and at two microwave powers (288 W, 624 W). Quality parameters were selected as bulk density, apparent density, apparent porosity, internal porosity, microstructure analysis, and color for dried cooked wheat; yield and water absorption capacity for bulgur. The dr...
OZILGEN, S; OZILGEN, M (Elsevier BV, 1991-05-01)
Thermal death kinetics of Escherichia coli with microwaves were studied by using a tubular flow reactor with different diameters, lengths, and flow rates. Mathematical models were presented for temperature profile development and death of the microorganisms along the reactor. A first-order kinetic expression in biomass concentration simulated the death phenomena. Temperature effects on the death rate constant were expressed with an Arrhenius expression. Numerical values of the constants of this expressi...
Respiratory parameters and sugar catabolism of mushroom (Agaricus bisporus Lange)
Varoquaux, P; Gouble, B; Barron, C; Yıldız, Fatih (Elsevier BV, 1999-05-01)
The respiration rate (RR) of mushroom (Agaricus bisporus Lange, strain X25) under air follows Arrhenius' law with an apparent activation energy of 43 400 J mol(-1) corresponding to a Q(10) of 2.9 between 10 and 20 degrees C. Oxygen from 20 to 1 kPa did not affect RR at temperatures ranging from 5 to 20 degrees C, confirming previous studies. The initial RR of mushroom (same cultivar, flush, growing conditions) measured 24 h after harvesting can vary from 1 to 2 mmol O-2 kg(-1) h(-1) at 10 degrees C. The app...
Citation Formats
F. Yöndem Makascıoğlu and T. Dik, “Use of a spouted bed to improve the storage stability of wheat germ followed in paper and polyethlyene packages,” Journal of the Science of Food and Agriculture, pp. 1329–1336, 2005, Accessed: 00, 2021. [Online]. Available: