Effect of temperature, pH and bacteriocins on the viability of selected food pathogens in food systems during high hydrostatic pressure (HHP) processing

Alpas, Hami


Effects of high hydrostatic pressure (HHP) on cellulose hydrolysis and cellulase activity, and its use for peanut hulls hydrolysis
Öztürk, Eylül; Alpas, Hami; Department of Food Engineering (2019)
High hydrostatic pressure (HHP) technique has potential for food preservation purposes and HHP treatment can inactivate enzymes and/or increase their activity. Avicel, the commercial name of microcrystalline cellulose, is a commonly used substrate to observe the activity of cellulase. Cellulase activity is a crucial parameter for the production of alternative renewable fuels. Celluclast 1.5L, a mixture of enzymes, are used for the hydrolysis of cellulose and hemicellulose containing substances. Peanut hull ...
Effect of high hydrostatic pressure and high dynamic pressure on stability and rheological properties of model oil-in-water emulsions
BIGIKOCIN, Erman; Mert, Behiç; Alpas, Hami (2011-01-01)
Both static and dynamic high pressure applications provide interesting modifications in food structures which lead to new product formulations. In this study, the effects of two different treatments, high hydrostatic pressure (HHP) and high dynamic pressure (HDP), on oil-in-water emulsions were identified and compared. Microfluidization was selected from among the HDP homogenization techniques. The performance of each process was analyzed in terms of rheological modifications and emulsion stability improvem...
Effect of High Hydrostatic Pressure (HHP) Treatment on Physicochemical Properties of Horse Mackerel (Trachurus trachurus)
ERKAN ÖZDEN, Nuray; Uretener, Gonca; Alpas, Hami; Selcuk, Arif; Ozden, Ozkan; Buzrul, Sencer (2011-10-01)
The basic objective of this study was to determine the effect of high hydrostatic pressure (HHP; 220, 250 and 330 MPa), holding time (5 and 10 min) and temperature (7, 15 and 25 A degrees C) on some quality parameters of horse mackerel such as colour changes, thiobarbituric acid (TBA-i) and trimethylamine nitrogen (TMA-N), free amino acid content. HHP increased L (*) values of horse mackerel. The a (*) and b (*) of treated horse mackerel did not change significantly after HHP applications. After, HHP, TBA-i...
Effect of high hydrostatic pressure and heat treatment on antimicrobial protein stability, shelf-life, and rheological characteristics of donkey milk
Köker, Alperen; Alpas, Hami; Öztürkoğlu-Budak, Şebnem; Department of Food Engineering (2021-11)
Donkey milk has been gaining popularity due to its beneficial properties and similarity to human milk, however, since heat treatment lead to phase seperation and nutritional losses, it is consumed raw, which may cause health risks and limit its shelf life. High hydrostatic pressure (HHP) is a non-thermal food processing technique in which microbial inactivation can be obtained with minimum effects on fresh like properties of food product. This study aimed to investigate the effects of HHP, and heat treatmen...
Effects of ultrasound and high pressure on physicochemical properties and HMF formation in Turkish honey types
Onur, Ipek; Mısra, N. N.; Barba, Francisco J.; Putnık, Predrag; Lorenzo, Jose M.; Gökmen, Vural; Alpas, Hami (2018-02-01)
In industrial production, thermal processing of honey at 50 degrees C commonly induces liquefaction, i.e. it reduces the crystal count and viscosity and delays any subsequent crystallization. Unfortunately, thermal treatment can generate toxic 5-hydroxymethylfurfural (HMF), thereby resulting in quality reduction. Considering this, the present work aims at evaluating the influence of (two) processing technologies as alternatives to thermal processing of honey, namely high hydrostatic pressure (HHP; P = 220-3...
Citation Formats
H. Alpas, “Effect of temperature, pH and bacteriocins on the viability of selected food pathogens in food systems during high hydrostatic pressure (HHP) processing,” Ph.D. - Doctoral Program, Middle East Technical University, 2000.