Inactivation kinetics of pectin methyl esterase under combined thermal–high pressure treatment in an orange juice–milk beverage

Effect of microwave assisted blanching on the ascorbic acid oxidase inactivation and vitamin C degradation in frozen mangoes

“…Similar fractional conversion kinetic models have been reported in avocado polyphenoloxidase inactivation under high pressure treatment (Weemaes, Ludikhuyze, Broeck, & Hendrickx, 1999), pectin methyl esterase in high pressure treated orange juice (Polydera, Stoforos, & Taoukis, 2005;Sampedro, Rodrigo, & Hendrickx, 2008) and carrots (LyNguyen et al, 2003). The fractional-conversion models is usually applied when a fraction is inactivated and another fraction remains constant and A∞, even after prolonged process treatment time.…”

Extending the Shelf Life of Fresh Marula (Sclerocarya birrea) Juice by Altering Its Physico-Chemical Parameters

“…It is also noted that the microbicidal activity of high pressure is enhanced by low pH or temperatures above and below ambient. High hydrostatic pressure acts primarily on non-covalent linkages, such as ionic bonds, hydrogen bonds and hydrophobic interactions, and it promotes reactions in which there is an overall decrease in volume (Adams and Moss, 1995;Indrawati et al, 2008;Sampedro et al, 2008;Chao, et al 2011). It can have profound effects on proteins, where such interactions are critical to structure and function, although the effect is variable and depends on individual protein structure.…”

“…As a general rule vegetative bacteria and fungi can be reduced by at least one log cycle by 400 MPa applied for 5 min. (Indrawati et al, 2008;Sampedro et al, 2008;Chao et al, 2011) Bacterial endospores are more resistant to hydrostatic pressure, tolerating pressures as high as 1200 MPa. Their susceptibility can be increased considerably by modest increases in temperature, when quite low pressures (100 MPa) can produce spore germination, a process in which the spores lose their resistance to heat and to elevated pressure.…”

“…Hydrostatic processing has a number of appealing features for the food preparations such as Marula fruit juice. (Indrawati, et al, 2008;Sampedro, et al, 2008;Chao, et al, 2011) It acts instantly and uniformly throughout a substance so that the processing time is not related to container size and there is none of the penetration problems associated with heat processing. Nutritional quality, flavour, appearance and texture resemble the fresh material very closely.…”

“…To the consumer where it has been used it is regarded as a 'natural' process with none of the negative associations of processes such as irradiation or chemical preservatives. ((Indrawati, et al, 2008;Sampedro, et al, 2008;Chao, et al, 2011) Appertized foods include those which are hermetically sealed into containers, usually cans, and then subjected to heat process in-pack. While this has been hugely successful as a long term method of food preservation, it does require extended heating periods in which a food's functional and chemical properties can be adversely affected.…”