(Bio)chemical reactions during high pressure/high temperature processing affect safety and quality of plant-based foods

Abstract

In recent years, the range of equipment and applications for high pressure pasteurization has gradually increased on the European market. Sterilization under conditions of elevated pressures is in the pipeline, albeit at the research level. Knowledge on the effect of high pressure/high temperature processing on food safety and quality attributes is still too limited. This review discusses recent progress made in understanding the impact of high pressure/high temperature processing on food safety and quality attributes of fruit and vegetable based products, within the EU FP6 integrated project NovelQ. Methodological approach for kinetic studies under HP/HT conditionsWhen performing a kinetic study, process parameters need to be, if not kept constant, at least documented as completely as possible. Rate constants strongly depend on pressure and temperature, both critical process parameters in HP/HT processing. Therefore, incorrectly assuming that process parameters are constant or inadequate knowledge of the temperature, pressure history will lead to incorrect estimates of the kinetic parameters (e.g. rate constants, activation energy and activation volume). Moreover these cannot then be extrapolated to different equipment (Van der Plancken et al., 2008). This is even more pertinent, when larger scale high pressure vessels are used, in which major temperature non-uniformity may arise (Grauwet, Van der Plancken,

Reducing peanut allergens by high pressure combined with polyphenol oxidase

“…According to Balny et al, [25] HP can induce hydration changes which in turn may cause protein structural changes and denaturation, and this phenomenon may explain why proteins in a solution are more unstable to HP than those in the dry state. However, in contrast to those studies, our current study and that of Van der Plancken et al [4] showed a different HP effect -that is, peanut allergens prepared in solutions were stable to HP rather than undergoing structural changes. Figure 3 shows the SDS-PAGE protein profiles of the untreated, PPO-, HP300/PPO-and HP500/PPO-treated peanut extracts at 3 and 10 min.…”

“…Our data are in agreement with the finding of Van der Plancken et al, [4] in which purified peanut allergens (Ara h 2 and Ara h 6) were found to be stable to HP between 150 and 800 MPa (10 min), and their structures remained unchanged even during HP treatment at 80 • C. By contrast, allergens from apples treated with HP at 80 • C exhibited structural changes and a reduction in immunoreactivity. [4,6] The high stability of peanut allergens to HP as shown in this study and that of Van der Plancken et al [4] is unusual because HP has previously been shown to induce protein denaturation, dissociation, or aggregation [8,15] and as a result, the HP-treated proteins are more easily digested and have a lower immunoreactivity. Also, HP can destabilize hydrophobic interactions, [24] which usually play a major role in the stabilization of protein tertiary structure.…”

“…It inactivates pathogens and maintains the nutritional and sensory properties of foods and fruit/vegetable juices. [1,2] Because of its ability to denature proteins and dissociate protein complexes, [3,4] HP has been applied to food allergens for reduction of their immunoreactivity. For instance, allergens from such foods as soybean, [5] apple, [6] carrot, [7] and beef [8] are reported to have to a lower immunoreactivity after HP treatment.…”

“…ovalbumin, bovine and soybean whey proteins) treated first with HP and then with proteolytic enzymes. [9][10][11] One study reports that HP has no effect on peanut allergens and their structures at room temperature or 80 • C. [4] However, when HP is applied in conjunction with a homogenization process, the degree of hydrolysis of peanut proteins/allergens by digestive enzymes was seen to increase, [9] suggesting that a combined method (i.e. HP and homogenization) helps to make peanut proteins/allergens more susceptible to hydrolysis by enzymes.…”

Recovery of genipin from genipap fruit by high pressure processing

“…Volume increased with the addition of enzymes and this was observed at all pressure levels. This might indicate a decrease in water absorption due to the activity of exogenous pectinases resulting in a polymer network breakdown (Van der Plancken et al, 2012). Further experiments should be carried out to confirm this hypothesis.…”