Sensitive Food Ingredients Research Articles

Antimicrobial properties of papaya (Vasconcellea pubescens) subjected to low-temperature vacuum dehydration

Low-Temperature Vacuum Drying (LTVD) could be considered an alternative to conventional food drying methods at high temperature in preserving bioactive compounds from foods. Thereby, the aim of this work was to evaluate the antioxidant and antimicrobial potential of papaya (Vasconcellea pubescens) pulp after LTVD compared to other drying methods including freeze-drying (FD), vacuum-drying (VD), convective-drying (CD) and infrared-drying (IRD). The drying rate was significantly influenced by the drying methods and temperatures. Compared with FD, LTVD resulted in a 52% decrease in drying time. Both disk-diffusion and minimal inhibitory concentration (MIC) assays showed increased antimicrobial activity for extracts prepared with dehydrated papaya. The lowest MIC (15.6 mg mL−1) was found against Bacillus cereus for extracts prepared with VD, CD and IRD papaya. All antioxidant compounds tested decreased after dehydration; however, a strong correlation was observed between DPPH and the antimicrobial activity against E. coli and B. cereus for all extracts prepared with dried papaya pulp. Therefore, dried papaya extracts can be good candidates for the development of natural preservatives regardless of the drying method used.Industrial relevance: Low-temperature vacuum dehydration (LTVD) is a novel technology that was initially developed for the drying of sensitive food ingredients. However, it is unknown if this technique can protect the heat sensitive antimicrobial compounds of fruits.

Encapsulation of rosemary essential oil

Encapsulation protects sensitive food ingredients against oxygen, heat, moisture, pH and it masks the unwanted taste of nutrients. The objective of the study was to encapsulate the rosemary essential oil in micron size and to find the optimum coating material formulation by investigating the physicochemical properties and storage stability of microcapsules. In the capsule preparation two different ratios of whey protein concentrate (WP) and maltodextrin (MD) (1:3 and 3:1), three different core to coating ratios (1:40, 1:20 and 1:10) and two different dextrose equivalent (DE) MD (DE:13–17 and DE:4–7) were used. Emulsions were analyzed for their particle size distributions and freeze dried capsules were analyzed for their drying efficiencies, encapsulation efficiencies, surface morphologies, and concentrations of 1,8-cineole during storage. Increasing WP:MD ratio was found to increase both drying and encapsulation efficiencies. Also, capsules having core to coating ratio of 1:20 and MD with DE:13–17 gave the highest drying and encapsulation efficiency values. Changing DE value of MD did not have any significant effect on particle size distributions and surface morphologies of the capsules. Lastly, encapsulation was found to be an effective method for increasing the storage stability of 1,8-cineole.

Associated-food-hazards: storage fungi and mites in poppy, mustard, lettuce and wheat

Storage fungi and mites frequently cause injury of crops and contamination of crop agro-products (= “sensitive food ingredients”) by allergens and toxins. This may have serious practical consequences since currently the food safety is one of the most important priorities of EU-agricultural policy. However, the risk of occurrence of biotic-hazard in various agricultural product and food ingredients is not equal since they differ in their sensitivity to infestation/contamination by various fungi- and mite-hazards. Therefore, the goal of our study was to identify and review the fungi-hazards connected with occurrence of 5 key-species of mite-hazards, in 4 kinds of “sensitive food ingredients” that include poppy, mustards, lettuce and wheat grain. Different numbers of fungal-hazards (wheat: 44, poppy: 37, mustard: 13, lettuce: 31) were isolated from the tested 4 kinds of crop agro-product. This indicates that their sensitivity to mite-associated fungal infestation/contamination increases in the following order: mustard, lettuce, poppy, and wheat. Mite-hazards differ in their vector-capacity of various fungi-hazards. Generally, predatory mites (i.e. Cheyletus spp.) represent lower risk than fungivorous and herbivorous species of mites (i.e. Acarus siro, Tyrophagus putrescentiae, Lepidoglyphus destructor, Caloglyphus rhizoglyphoides) in terms of vectoring fungi hazards. Many of the mites and fungi hazards rarely occurred independently. We therefore propose that (i) such pest-hazard-systems (i.e. fungi-mite-hazard-systems) should be called “associated-hazards” (ii) the new and specific approaches to risk assessment of “associated hazards” should be developed and implemented into practice.