Quality improvement of manuka honey through the application of high pressure processing

The quality of honey is known to be compromised when it goes through thermal processing due to its negative impact on the unstable and thermolabile honey components which originated from the nectar and bees themselves. This present work is undertaken to access the use of an emerging food preservation technique known as “High Pressure Processing” for treating honey, as an alternative to the conventional thermal processing. In this thesis, honey quality has been addressed by measuring the effects of high pressure processing parameters (pressure, time and temperature) on nutritional properties of honey, namely total phenolic content and antioxidant activity. Honey samples, contained in small pouches, were subjected to different pressures (200-600 MPa) at close to ambient temperatures (25-33°C) for different holding times (10 to 30 min). Thermal processing (49- 70°C) was also carried out for comparison purpose. Results demonstrated that high pressure processing operated at 600 MPa for 10 min has capability to increase significantly the total phenolic content and antioxidant activity by 47% and 30%, respectively. Besides, the result showed that high pressure processing can maintain the natural colour of honey which relates directly to consumer perception, while retaining its shear-thinning behaviour and viscosity with no significant changes (p > 0.05). High pressure processing can also control hydroxymethylfurfural (HMF) concentration in honey during process within the standard limit, 16.93 to 18.76 mg/kg (which is below than the maximum allowed limit of 40 mg/kg). This work also reveals that high pressure processing can enhance antibacterial activity of Manuka honey significantly. It shows an increase in the percentage inhibition of Staphylococcus epidermidis from 64.15 ± 5.86% to 84.34 ± 7.62% when honey was subjected to 600 MPa. Storage studies for one year at room temperature (25°C) demonstrated that high pressure-treated samples have a good retention to the physicochemical, nutritional and rheological properties of honey throughout storage, which confirms that the positive effect of high pressure on honey is not a temporary effect. Whereas, an insight study on the safety part showed that the Saccharomyces cerevisiae cell varied linearly with ° Brix, indicating that food compressibility has a significant role in the microbial inactivation

Experimental data from flesh quality assessment and shelf life monitoring of high pressure processed European sea bass (Dicentrarchus labrax) fillets

Fresh fish are highly perishable food products and their short shelf-life limits their commercial exploitation and leads to waste, which has a negative impact on aquaculture sustainability. New non-thermal food processing methods, such as high pressure (HP) processing, prolong shelf-life while assuring high food quality. The effect of HP processing (600MPa, 25 °C, 5min) on European sea bass (Dicentrarchus labrax) fillet quality and shelf life was investigated. The data presented comprises microbiome and proteome profiles of control and HP-processed sea bass fillets from 1 to 67 days of isothermal storage at 2 °C. Bacterial diversity was analysed by Illumina high-throughput sequencing of the 16S rRNA gene in pooled DNAs from control or HP-processed fillets after 1, 11 or 67 days and the raw reads were deposited in the NCBI-SRA database with accession number PRJNA517618. Yeast and fungi diversity were analysed by high-throughput sequencing of the internal transcribed spacer (ITS) region for control and HP-processed fillets at the end of storage (11 or 67 days, respectively) and have the SRA accession number PRJNA517779. Quantitative label-free proteomics profiles were analysed by SWATH-MS (Sequential Windowed data independent Acquisition of the Total High-resolution-Mass Spectra) in myofibrillar or sarcoplasmic enriched protein extracts pooled for control or HP-processed fillets after 1, 11 and 67 days of storage. Proteome data was deposited in the ProteomeXchange Consortium via the PRIDE partner repository with the dataset identifiers PXD012737. These data support the findings reported in the associated manuscript "High pressure processing of European sea bass (Dicentrarchus labrax) fillets and tools for flesh quality and shelf life monitoring", Tsironi et al., 2019, JFE 262:83-91, doi.org/10.1016/j.jfoodeng.2019.05.010.FCT (Foundation of Science and Technology) COFASP/0002/2015; Portuguese Foundation for Science and Technology UID/Multi/04326/2019 POCI-01-0145-FEDER007440 UID/NEU/04539/2019info:eu-repo/semantics/publishedVersio

Qualitative features of organic tomatoes

In recent years, the organic sector has put significant efforts in the development of clear definitions for gentle and quality oriented processing of plant based foodstuffs to supplement existing regulations. Concrete quality standards for different types of processing are under development in several CoreOrganic Plus projects. However, there is still a significant need for development of a Code of Practice. Quality of a product and sustainability of production depend on the cumulative impacts of each processing step in the food chain, as well as the quality of the raw material. With increasing demands by the consumers who expect high quality foods produced sustainably and preferably regionally (SusOrganic consumer survey), pressure on the producers is growing as this requires skilled and qualified agri-food practitioners, professionals and manufacturers to be able to deliver the best quality at affordable prices and the lowest environmental impact possible

Stabilization of Arthrospira platensis with high-pressure processing and thermal treatments: Effect on physico-chemical and microbiological quality

Arthrospira platensis (Spirulina) is a cyanobacterium that has been recently studied for food applications due to its high biological and nutritional value. When A. platensis is used as an ingredient in food applications, proper treatments have to be applied in order to reduce microbial contamination. This work compared the effect of thermal treatments (sterilization at 121℃ and pasteurization at 90℃) and high-pressure processing (400, 600 MPa) on the chemical, physico-chemical, and microbial quality of 5% (wt/vol) A. platensis aqueous suspensions. Total antioxidant capacity, total polyphenols content, color, and pigments content were not strongly lowered/modified by the high-pressure processing (HPP) treatments. HPP at 400 MPa even improved the release of C-phycocyanin from the biomass because of the breakage of cell walls. HPP treatments were comparable to pasteurization in reducing yeasts, coliforms, Staphylococci, and total bacterial count. Conversely, sterilization was the only treatment that guaranteed the inactivation of spore-forming species but affecting the final quality. Novelty impact statement: High-pressure processing (HPP) treatments were found to be a good strategy to preserve or even improve some physical and chemical properties of Arthrospira platensis (Spirulina), in particular antioxidant capacity, polyphenols, color, and pigments content. Furthermore, HPP treatments were comparable to pasteurization in reducing microbial cell count, while sterilization was the only treatment able to ensure the inhibition of spore-forming species

Edible insect processing pathways and implementation of emerging technologies

The processing of insects is paramount to deliver safe and high quality raw materials, ingredients and products for large-scale food and feed applications. Depending upon the nature of the initial material and the desired end product, the processing pathways vary and may include several unit operations currently already used in food and feed processing. Insect processing pathways can involve harvesting, pre-processing, decontamination, further processing, packaging and storage. Several traditional and industrial decontamination methods have been proposed for edible insects, which include smoking, drying, blanching/boiling, marination, cooking, steaming, toasting and their combinations. Further processing steps are employed to produce insect meal, insect flour or extracted insect fractions. Each operation will have a different impact on the chemical and microbiological properties of the final product. Novel food processing technologies (e.g. high pressure processing, pulsed electric field, ultrasound and cold plasma) have shown potential to modify, complement or replace the conventional processing steps in insect processing. These technologies have been tested for microbial decontamination, enzyme inactivation, drying and extraction. Further, these are considered to be environmentally friendly and may be implemented for versatile applications to improve the processing efficiency, safety and quality of insect based products. Future research focuses in insect processing are development of efficient, environmentally friendly and low-cost processes; waste minimisation and incorporation of by-products/co-products

Twin-screw extrusion technology for vegetable oil extraction: A review

Vegetable oils present a valuable class of bioresources with applications in both food and non-food industries and a production that has been steadily increasing over the past twenty years. Their extraction from oilseeds is a key process, as it exerts a strong impact on the resulting oil characteristics and quality. In view of the recent pressure towards sustainability, oilseed processing industries are taking renewed interest in thermomechanical pressing as a means to obtain high quality oils. This work focuses on twin-screw extrusion for vegetable oil extraction and reviews recent technological advancements and research challenges for the design and optimization of novel oil extraction processes. It comprises a critical analysis of the application of twin-screw extruders against their more conventional single-screw counterparts. Further, a comprehensive overview of the key parameters influencing the process performance is provided, while considerable attention is given to the development of innovative green extraction processes using twin-screw extrusion

Impact of cold atmospheric pressure plasma processing on storage of blueberries

The current study aimed at investigating the impact of nitrogen (N)-generated cold atmospheric pressure plasma (CAPP) treatment on blueberries focusing on the overall impact on berry quality and microbial load along a storage period of 10 days. Blueberries were treated for 0 (control), 5, and 10 min. Assessment of fruit quality (°Bx, ascorbic acid, anthocyanins, titratable acidity, elasticity, and color parameters) and microbial analysis was performed. Results showed that CAPP treatment was more effective in inhibiting bacterial growth than fungal growth and during the subsequent storage, the quality parameters did not differ significantly from the control, under the same conditions. The study supports N-generated CAPP as a disinfection technique to reduce microbial load in blueberries without significantly impacting most quality parameters. Practical applications: Over the last decades, foodborne illness outbreaks around the world have been associated with berries. For that reason, due to the increasing consumption of berries it is paramount to study technologies that can eliminate pathogens responsible for such outbreaks. Cold atmospheric pressure plasma (CAPP) can be a promising technology to be used as an alternative to traditional decontamination methods of food. In this context, this study explored the effect and efficiency of this novel technology on reduction of native microflora and its impact on the physical and chemical properties of blueberries treated by nitrogen (N)-generated CAPP with subsequent storage of 10 days. Results of this work confirmed that such technology has high potential application for decontamination of berries without significantly impacting most quality parameters and thereby can be a potential technology for industrial applications. © 2020 The Authors. Journal of Food Processing and Preservation published by Wiley Periodicals LLC

High pressure treatment and green tea extract synergistically control enteric virus contamination in beverages

Consumers are driving food production toward the use of natural preservatives and minimal processing technologies. Green tea extract (GTE) at low concentration could be combined with high pressure processing (HPP) for reduced treatment times and quality impact on foods in a hurdle concept for synergistic effects on foodborne viral pathogens, specifically human norovirus and hepatitis A virus (HAV). Viral inactivation by HPP (at 300, 400, and 500 MPa for 5 min) combined with 3.3 mg/mL aged-GTE was initially evaluated in buffer (PBS) against murine norovirus (MNV), a culturable human norovirus surrogate, and HAV. Furthermore, human norovirus inactivation was evaluated by the novel human intestinal enteroid system (HIE) and a capsid integrity binding assay (ISC-RT-qPCR). HPP treatment completely inhibits human norovirus GII.4 infectivity when applied at 500 MPa alone and at 400 MPa combined with aged-GTE. Additional experiments investigated the reduction of MNV and HAV infectivity in apple and horchata juices exposed to combined aged-GTE and HPP treatments. Results demonstrated that the addition of aged-GTE to the juices exposed to HPP significantly inactivated MNV and HAV at reduced holding pressure time. This synergistic effect of aged-GTE combined with HPP treatments represents a hurdle technology that could be exploited as a control measure to improve the food safety of beverages

Optimization of injection molding parameter in processing polypropylene using Taguchi method / Mohamad Adib Adam Abd Wahab

Nowadays, manufacturing industry is growing rapidly in any country over the world. Plastic industry is the one of the manufacturing industry that has high demand products to consumers. Polypropylene is popular due to its characteristics such as recycle, low cost, chemical resistance, excellent impact strength, food grade availability and so on. The plastic product were produced by using injection molding machine at different injection molding parameters. The quality of product depends on the optimization of the injection molding parameter that will be set for producing plastic product. Thus, the optimization of the injection molding parameter on processing polypropylene by using design of experiment is the main objective of the study. The shrinkage and cycle time fabrication of polypropylene were investigated. Shrinkage is inherent in the injection molding process. This is because the density of polymer was different from the processing temperatures compared to the ambient temperature. The best value of injection molding parameters such as melting temperature, injection pressure, injection speed, cooling time, holding time and holding pressure have been obtained and optimized. From the results obtained, the most significant injection molding parameter on shrinkage and cycle time fabrication of polypropylene is holding time. The result has been supported by analysis of variance (Anova). By using design of experiment method, it has eliminate the trial and error method and save time and money in development and processing the plastic product. The optimization of injection molding parameter contributes to the plastic processing such as increasing productivity, quality and reliability of the product. The surface morphology of specimen hard to see because the polypropylene is semi crystalline polymer

Effects of killing methods on lipid oxidation, colour and microbial load of black soldier fly (Hermetia illucens) larvae

The projected global population growth by 2050 will require an increase in the production of high-quality food. Insects represent a promising alternative ingredient for feed with a lower environmental impact than conventional livestock such as poultry, swine and bovine species. In a context of commercial-scale production and considering the great diversity of insects, it is crucial to optimize the processing steps, including those used to kill insects. In addition to being able to maximize the nutritional and microbiological quality of the final product, insect killing methods should be rapid and effective. This project aims to optimize killing methods, i.e., blanching, desiccation, freezing (−20 °C; −40 °C; liquid nitrogen), high hydrostatic pressure, grinding and asphyxiation (CO2; N2; vacuum conditioning), and to evaluate their impact on the composition, lipid oxidation, colour and microbiological quality on the black soldier fly larvae. Blanching appears to be the most appropriate strategy since it is a rapid and effective killing method reducing larval moisture while minimizing lipid oxidation, microbial contamination and colour alteration. Ultimately, this work will help to establish a standardized protocol that meets the Canadian regulatory quality requirements for feed. Abstract : Black soldier fly (BSF) larvae represent a promising alternative ingredient for animal feed. Post-production processing can, however, affect their quality. This project aimed to optimize larval killing by comparing the effects on the nutritional and microbiological quality of 10 methods, i.e., blanching (B = 40 s), desiccation (D = 60 °C, 30 min), freezing (F20 = −20 °C, 1 h; F40 = −40 °C, 1 h; N = liquid nitrogen, 40 s), high hydrostatic pressure (HHP = 3 min, 600 MPa), grinding (G = 2 min) and asphyxiation (CO2 = 120 h; N2 = 144 h; vacuum conditioning, V = 120 h). Some methods affected the pH (B, asphyxiation), total moisture (B, asphyxiation and D) and ash contents (B, p < 0.001). The lipid content (asphyxiation) and their oxidation levels (B, asphyxiation and D) were also affected (p < 0.001). Killing methods altered the larvae colour during freeze-drying and in the final product. Blanching appears to be the most appropriate strategy since it minimizes lipid oxidation (primary = 4.6 ± 0.7 mg cumen hydroperoxide (CHP) equivalents/kg; secondary = 1.0 ± 0.1 mg malondialdehyde/kg), reduces microbial contamination and initiates dehydration (water content = 78.1 ± 1.0%). We propose herein, an optimized protocol to kill BSF that meet the Canadian regulatory requirements of the insect production and processing industry