Bioequivalence of long-chain omega-3 polyunsaturated fatty acids from foods enriched with a novel vegetable-based omega-3 delivery system compared to gel capsules: a randomized controlled cross-over acute trial.

PURPOSE: To evaluate bioavailability of omega-3 long-chain polyunsaturated fatty acids (LCPUFA) from foods enriched with novel vegetable-based encapsulated algal oil across Australian and Singaporean populations. METHODS: 27 men (n = 12 Australian European; n = 15 Singaporean Chinese), 21-50 yr; 18-27.5 kg/m2, with low habitual intake of omega-3 LCPUFA completed a multicentre randomised controlled acute 3-way cross-over single-blind trial. They consumed, in random order 1-week apart after an overnight fast, standard breakfast meals including 400 mg docosahexanoic acid (DHA) from either extruded rice snacks or soup both containing cauliflower-encapsulated HiDHA® algal oil or gel capsules containing HiDHA® algal oil. Blood samples for analysis of plasma DHA and eicosapentaenoic acid (EPA) were taken pre-meal and after 2, 4, 6, 8 and 24 h. Primary analyses comparing 24-h incremental area under the plasma DHA, EPA and DHA + EPA concentration (µg/ml) curves (iAUC0-24 h) between test foods were performed using linear mixed models by including ethnicity as an interaction term. RESULTS: Plasma iAUC0-24 h did not differ significantly between test foods (adjusted mean [95% CI] plasma DHA + EPA: extruded rice snack, 8391 [5550, 11233] µg/mL*hour; soup, 8862 [6021, 11704] µg/mL*hour; capsules, 11,068 [8226, 13910] µg/mL*hour, P = 0.31) and did not differ significantly between Australian European and Singaporean Chinese (treatment*ethnicity interaction, P = 0.43). CONCLUSION: The vegetable-based omega-3 LCPUFA delivery system did not affect bioavailability of omega-3 LCPUFA in healthy young Australian and Singaporean men as assessed after a single meal over 24 h, nor was bioavailability affected by ethnicity. This novel delivery system may be an effective way to fortify foods/beverages with omega-3 LCPUFA. TRIAL REGISTRATION: The trial was registered with clinicaltrials.gov (NCT04610983), date of registration, 22 November 2020.

Inhibitory effects of organic acids on polyphenol oxidase: From model systems to food systems.

Organic acids are widely utilized in the food industry for inhibiting the activity of polyphenol oxidase (PPO) and enzymatic browning. This review discusses the mechanisms of inhibition of PPO and enzymatic browning by various organic acids based on studies in model systems, critically evaluates the relevance of such studies to real food systems and assesses the implication of the synergistic inhibitory effects of organic acids with other physicochemical processing techniques on product quality and safety. Organic acids inhibit the activity of PPO and enzymatic browning via different mechanisms and therefore the suitability of a particular organic acid depends on the structure and the catalytic properties of PPO and the physicochemical properties of the food matrix. Studies in model systems provide an invaluable insight into the inhibitory mechanisms of various organics acids. However, the difference in the effectiveness of PPO inhibitors between model systems and food systems and the lack of correlation between the degree of PPO inhibition based on in vitro assays and enzymatic browning imply that the effectiveness of organic acids can be accurately evaluated only via direct assessment of browning inhibition in a particular food system. Combination of organic acids with physical processing techniques is one of the most viable approaches for PPO inhibition since the observed synergistic effect helps to reduce the undesirable organoleptic quality changes from the use of excessive concentration of organic acids or intense physical processing.

Quality-related enzymes in plant-based products: effects of novel food-processing technologies part 3: ultrasonic processing.

High-power ultrasound is a versatile technology which can potentially be used in many food processing applications including food preservation. This is part 2 of a series of review articles dealing with the effectiveness of nonthermal food processing technologies in food preservation focusing on their effect on enzymes. Typically, ultrasound treatment alone does not efficiently cause microbial or enzyme inactivation sufficient for food preservation. However, combined with mild heat with or without elevated pressure (P ≤ 500 kPa), ultrasound can effectively inactivate enzymes and microorganisms. Synergistic effects between ultrasound and mild heat have been reported for the inactivation of both enzymes and microorganisms. The application of ultrasound has been shown to enhance the rate of inactivation of quality degrading enzymes including pectin methylesterase (PME), polygalacturonase (PG), peroxidase (POD), polyphenol oxidase (PPO), and lipoxygenase (LOX) at mild temperature by up to 400 times. Moreover, ultrasound enables the inactivation of relatively heat-resistant enzymes such as tomato PG1 and thermostable orange PME at mild temperature conditions. The extent to which ultrasound enhances the inactivation rate depends on the type of enzyme, the medium in which the enzyme is suspended, and the processing condition including frequency, ultrasonic intensity, temperature, and pressure. The physical and chemical effects of cavitation are considered to be responsible for the ultrasound-induced inactivation of enzymes, although the dominant mechanism depends on the structure of the enzyme.

Quality-related enzymes in plant-based products: effects of novel food processing technologies part 2: pulsed electric field processing.

Pulsed electric field (PEF) processing is an effective technique for the preservation of pumpable food products as it inactivates vegetative microbial cells at ambient to moderate temperature without significantly affecting the nutritional and sensorial quality of the product. However, conflicting views are expressed about the effect of PEF on enzymes. In this review, which is part 2 of a series of reviews dealing with the effectiveness of novel food preservation technologies for controlling enzymes, the scientific literature over the last decade on the effect of PEF on plant enzymes is critically reviewed to shed more light on the issue. The existing evidence indicates that PEF can result in substantial inactivation of most enzymes, although a much more intense process is required compared to microbial inactivation. Depending on the processing condition and the origin of the enzyme, up to 97% inactivation of pectin methylesterase, polyphenol oxidase, and peroxidase as well as no inactivation have been reported following PEF treatment. Both electrochemical effects and Ohmic heating appear to contribute to the observed inactivation, although the relative contribution depends on a number of factors including the origin of the enzyme, the design of the PEF treatment chamber, the processing condition, and the composition of the medium.

Quality-related enzymes in fruit and vegetable products: effects of novel food processing technologies, part 1: high-pressure processing.

The activity of endogenous deteriorative enzymes together with microbial growth (with associated enzymatic activity) and/or other non-enzymatic (usually oxidative) reactions considerably shorten the shelf life of fruits and vegetable products. Thermal processing is commonly used by the food industry for enzyme and microbial inactivation and is generally effective in this regard. However, thermal processing may cause undesirable changes in product's sensory as well as nutritional attributes. Over the last 20 years, there has been a great deal of interest shown by both the food industry and academia in exploring alternative food processing technologies that use minimal heat and/or preservatives. One of the technologies that have been investigated in this context is high-pressure processing (HPP). This review deals with HPP focusing on its effectiveness for controlling quality-degrading enzymes in horticultural products. The scientific literature on the effects of HPP on plant enzymes, mechanism of action, and intrinsic and extrinsic factors that influence the effectiveness of HPP for controlling plant enzymes is critically reviewed. HPP inactivates vegetative microbial cells at ambient temperature conditions, resulting in a very high retention of the nutritional and sensory characteristics of the fresh product. Enzymes such as polyphenol oxidase (PPO), peroxidase (POD), and pectin methylesterase (PME) are highly resistant to HPP and are at most partially inactivated under commercially feasible conditions, although their sensitivity towards pressure depends on their origin as well as their environment. Polygalacturonase (PG) and lipoxygenase (LOX) on the other hand are relatively more pressure sensitive and can be substantially inactivated by HPP at commercially feasible conditions. The retention and activation of enzymes such as PME by HPP can be beneficially used for improving the texture and other quality attributes of processed horticultural products as well as for creating novel structures that are not feasible with thermal processing.

Microencapsulation technology for delivery of enzymes in ruminant feed.

The ruminant digestive system is uniquely designed to make efficient use of high-fibre feed, including forages. Between 40 to 100% of the ruminant diet consists of forages which are high in fibre and up to 70% of this may remain undigested in the ruminant gut, with substantial impact on feed utilisation rate and productivity and the economic and environmental sustainability of livestock production systems. In ruminants, feed costs can make up to 70% of the overall cost of producing an animal product. Increasing feed utilisation efficiency, i.e., more production with less feed lowers feeding costs and improves livestock economic viability. Strategies for improving nutrient utilisation in animal feed has been investigated over the years. Incorporation of fibre digesting enzymes in the feed to facilitate the digestion of the residual fibre in hind gut is one of the proposed strategies. However, delivering such enzymes to the hind gut in active state is challenging due to the unfavourable biochemical environment (pH, microbial proteases) of ruminant's gastrointestinal tract. This review discusses the potential application of microencapsulation for protected and targeted delivery of enzymes into the hind gut of ruminants.

The stability of almond ß-glucosidase during combined high pressure-thermal processing: a kinetic study.

The thermal and the combined high pressure-thermal inactivation kinetics of almond ß-glucosidase (ß-D-glucoside glucohydrolase, EC 3.2.1.21) were investigated at pressures from 0.1 to 600 MPa and temperatures ranging from 30 to 80 °C. Thermal treatments at temperatures higher than 50 °C resulted in significant inactivation with complete inactivation after 2 min of treatment at 80 °C. Both the thermal and high pressure inactivation kinetics were described well by first-order model. Application of pressure increased the inactivation kinetics of the enzyme except at moderate temperatures (50 to 70 °C) and pressures between 0.1 and 100 MPa where slight pressure stabilisation of the enzyme against thermal denaturation was observed. The activation energy for the inactivation of the enzyme at atmospheric pressure was estimated to be 216.2±8.6 kJ/mol decreasing to 55.2±3.9 kJ/mol at 600 MPa. The activation volumes were negative at all temperature conditions excluding the temperature-pressure range where slight pressure stabilisation was observed. The values of the activation volumes were estimated to be -29.6±0.6, -29.8±1.7, -20.6±3.2, -41.2±4.8, -36.5±1.8, -39.6±4.3, -31.0±4.5 and -33.8±3.9 cm3/mol at 30, 35, 40, 45, 50, 60, 65 and 70 °C, respectively, with no clear trend with temperature. The pressure-temperature dependence of the inactivation rate constants was well described by an empirical third-order polynomial model.

High Pressure Processing Applications in Plant Foods.

High pressure processing (HPP) is a cold pasteurization technology by which products, prepacked in their final package, are introduced to a vessel and subjected to a high level of isostatic pressure (300-600 MPa). High-pressure treatment of fruit, vegetable and fresh herb homogenate products offers us nearly fresh products in regard to sensorial and nutritional quality of original raw materials, representing relatively stable and safe source of nutrients, vitamins, minerals and health effective components. Such components can play an important role as a preventive tool against the start of illnesses, namely in the elderly. An overview of several food HPP products, namely of fruit and vegetable origin, marketed successfully around the world is presented. Effects of HPP and HPP plus heat on key spoilage and pathogenic microorganisms, including the resistant spore form and fruit/vegetable endogenous enzymes are reviewed, including the effect on the product quality. Part of the paper is devoted to the industrial equipment available for factories manufacturing HPP treated products.

How Healthy Are Non-Traditional Dietary Proteins? The Effect of Diverse Protein Foods on Biomarkers of Human Health.

Future food security for healthy populations requires the development of safe, sustainably-produced protein foods to complement traditional dietary protein sources. To meet this need, a broad range of non-traditional protein foods are under active investigation. The aim of this review was to evaluate their potential effects on human health and to identify knowledge gaps, potential risks, and research opportunities. Non-traditional protein sources included are algae, cereals/grains, fresh fruit and vegetables, insects, mycoprotein, nuts, oil seeds, and legumes. Human, animal, and in vitro data suggest that non-traditional protein foods have compelling beneficial effects on human health, complementing traditional proteins (meat/poultry, soy, eggs, dairy). Improvements in cardiovascular health, lipid metabolism, muscle synthesis, and glycaemic control were the most frequently reported improvements in health-related endpoints. The mechanisms of benefit may arise from their diverse range of minerals, macro- and micronutrients, dietary fibre, and bioactive factors. Many were also reported to have anti-inflammatory, antihypertensive, and antioxidant activity. Across all protein sources examined, there is a strong need for quality human data from randomized controlled intervention studies. Opportunity lies in further understanding the potential effects of non-traditional proteins on the gut microbiome, immunity, inflammatory conditions, DNA damage, cognition, and cellular ageing. Safety, sustainability, and evidence-based health research will be vital to the development of high-quality complementary protein foods that enhance human health at all life stages.

Thermosonication for the Production of Sulforaphane Rich Broccoli Ingredients.

A large proportion of broccoli biomass is lost during primary production, distribution, processing, and consumption. This biomass is rich in polyphenols and glucosinolates and can be used for the production of bioactive rich ingredients for food and nutraceutical applications. This study evaluated thermosonication (TS) (18 kHz, 0.6 W/g, 40-60 °C, 3-7 min) for the pre-treatment of broccoli florets to enhance enzymatic conversion of glucoraphanin into the bioactive sulforaphane. TS significantly increased sulforaphane yield, despite a decrease in myrosinase activity with increasing treatment intensity. The highest sulforaphane yield of ~2.9 times that of untreated broccoli was observed for broccoli thermosonicated for 7 min at 60 °C, which was 15.8% higher than the corresponding yield for thermal processing without sonication (TP) at the same condition. This was accompanied by increase in the residual level of glucoraphanin (~1.8 and 2.3 time respectively after TP and TS at 60 °C for 7 min compared to control samples) indicating that treatment-induced release of bound glucoraphanin from the cell wall matrix and improved accessibility could be at least partially responsible for the enhanced sulforaphane yield. The result indicates the potential of TS for the conversion of broccoli biomass into high sulforaphane broccoli-based ingredients.

Mild heat combined with lactic acid fermentation: a novel approach for enhancing sulforaphane yield in broccoli puree.

This study evaluated for the first time the feasibility of mild preheating treatment of broccoli florets combined with lactic acid bacteria fermentation for enhancing sulforaphane yield in broccoli puree. The optimum preheating condition for in-pack processing of broccoli florets was 3 min treatment at 65 °C increasing sulforaphane yield in broccoli puree by ∼5 times compared to untreated broccoli. Preheating of broccoli florets in-pack (65 °C per 3 min) combined with lactic acid bacteria fermentation further enhanced the sulforaphane content by ∼16 times compared to untreated broccoli. The sulforaphane content of the preheated-fermented puree remained stable (∼94% retention) for two weeks at 4 °C. The results indicate that a combination of judicious heat treatment of broccoli florets with lactic acid bacteria fermentation enables production of safe and high sulforaphane content broccoli products with potential health benefits.

Fermentation by Probiotic Lactobacillus gasseri Strains Enhances the Carotenoid and Fibre Contents of Carrot Juice.

Carrot juice (straight, 8.5 Brix and concentrated, 15.2 Brix) was fermented by lactic acid bacteria (Lactobacillus gasseri strain DSM 20604 or DSM 20077). Fermentation enhanced the nutritional profile of carrot juice. There was a greater sugar reduction (27%) in fermented straight carrot juices than in the fermented concentrated juices (15%). The sugar reduction was independent of the strain used for fermentation. The two L. gasseri strains synthesised fructosyltransferase enzymes during fermentation of carrot juice samples that enabled conversion of simple sugars primarily into polysaccharides. The level of conversion to polysaccharides was dependent on the L. gasseri strain and juice concentration. Fermentation of carrot juice by L. gasseri enables the production of a nutritionally-enhanced beverage with reduced calorie and prebiotic potential. An additional benefit is the increased carotenoid content observed in straight and concentrated juices fermented by Lactobacillus gasseri DSM 20077 and the concentrated juice fermented by Lactobacillus gasseri DSM 20604.

Fermentation-based biotransformation of glucosinolates, phenolics and sugars in retorted broccoli puree by lactic acid bacteria.

This study investigated the effect of lactic acid bacteria (LAB) fermentation on the chemical profile of autoclaved broccoli puree, using 7 broccoli-derived LAB isolates (named F1-F5, BF1 and BF2). The total concentrations of glucosinolates (glucoiberin, progoitrin and glucoraphanin) and 10 major phenolics significantly increased from trace level and 289 µg total phenolics/g dry weight (DW) respectively in autoclaved broccoli to 55 to ∼359 µg/g DW and 903 to ∼3105 µg/g DW respectively in LAB fermented broccoli puree. Differential impacts of LAB isolates on the chemical composition of autoclaved broccoli were observed, with the major differences being the significant increase in phloretic acid after fermentation by F1-F5 and an elevated glucoraphanin level in ferments by F1 and BF2. LAB fermentation is a promising way to increase the content of glucosinolates and polyphenolic compounds in broccoli, making the ferments attractive for use as functional ingredients or as a whole functional food.

Thermal and high pressure inactivation kinetics of blueberry peroxidase.

This study for the first time investigated the stability and inactivation kinetics of blueberry peroxidase in model systems (McIlvaine buffer, pH=3.6, the typical pH of blueberry juice) during thermal (40-80°C) and combined high pressure-thermal processing (0.1-690MPa, 30-90°C). At 70-80°C, the thermal inactivation kinetics was best described by a biphasic model with ∼61% labile and ∼39% stable fractions at temperature between 70 and 75°C. High pressure inhibited the inactivation of the enzyme with no inactivation at pressures as high as 690MPa and temperatures less than 50°C. The inactivation kinetics of the enzyme at 60-70°C, and pressures higher than 500MPa was best described by a first order biphasic model with ∼25% labile fraction and 75% stable fraction. The activation energy values at atmospheric pressure were 548.6kJ/mol and 324.5kJ/mol respectively for the stable and the labile fractions.

Data on blueberry peroxidase kinetic characterization and stability towards thermal and high pressure processing.

The data presented in this article are related to a research article entitled 'Thermal and high pressure inactivation kinetics of blueberry peroxidase' (Terefe et al., 2017) [1]. In this article, we report original data on the activity of partially purified blueberry peroxidase at different concentrations of hydrogen peroxide and phenlylenediamine as substrates and the effects of thermal and high pressure processing on the activity of the enzyme. Data on the stability of the enzyme during thermal (at temperatures ranging from 40 to 80 °C) and combined thermal-high pressure processing (100-690 MPa, 30-90 °C) are included in this report. The data are presented in this format in order to facilitate comparison with data from other researchers and allow statistical analyses and modeling by others in the field.

Effects of cryostabilizers, low temperature, and freezing on the kinetics of the pectin methylesterase-catalyzed de-esterification of pectin.

The kinetics of the pectin methylesterase (PME)-catalyzed de-esterification of pectin was studied at 25 degrees C in the presence of sucrose, fructose, maltodextrin (DE = 16.5-19.5), and carboxymethylcellulose at different concentrations and in the presence of maltodextrin and sucrose at different concentrations in a temperature range between +25 and -4 degrees C in subcooled and frozen states. The objective was to determine whether the reaction is diffusion-controlled, to gain insight about the factors determining the diffusion of the reactants, and to determine the effect of the carbohydrates, low temperature, and freezing on the structural conformation of the enzyme. The results indicate that the PME-catalyzed de-esterification of pectin is diffusion-controlled. Nevertheless, the diffusion is not controlled by the macroviscosity of the reaction medium, but rather by the microviscosity experienced by the diffusants. Low temperature in the temperature range studied does not affect the structural conformation of the enzyme, while freezing seems to have some effect.

Blueberry polyphenol oxidase: Characterization and the kinetics of thermal and high pressure activation and inactivation.

Partially purified blueberry polyphenol oxidase (PPO) in Mcllvaine buffer (pH=3.6, typical pH of blueberry juice) was subjected to processing at isothermal-isobaric conditions at temperatures from 30 to 80 °C and pressure from 0.1 to 700 MPa. High pressure processing at 30-50 °C at all pressures studied caused irreversible PPO activity increase with a maximum of 6.1 fold increase at 500 MPa and 30 °C. Treatments at mild pressure-mild temperature conditions (0.1-400 MPa, 60 °C) also caused up to 3 fold PPO activity increase. Initial activity increase followed by a decrease occurred at relatively high pressure-mild temperature (400-600 MPa, 60 °C) and mild pressure-high temperature (0.1-400 MPa, 70-80 °C) combinations. At temperatures higher than 76 °C, monotonic decrease in PPO activity occurred at 0.1 MPa and pressures higher than 500 MPa. The activation/inactivation kinetics of the enzyme was successfully modelled assuming consecutive reactions in series with activation followed by inactivation.

Kinetics of the pectin methylesterase catalyzed de-esterification of pectin in frozen food model systems.

The pectin methylesterase (PME) catalyzed de-esterification of pectin was studied in four frozen food model systems based on sucrose, fructose, maltodextrin, and carboxymethylcellulose (CMC) in a temperature range from -24 to 20 degrees C, with the aim of elucidating the applicability of the theory of "food polymer science" on the kinetics. The rate substantially decreased around the glass transition temperature in the case of CMC, while very low rates were observed far above the glass transition temperature in the case of maltodextrin, fructose, and sucrose model systems. In general, the kinetics of this reaction was found to be influenced more by factors such as the characteristics of the component solutes, freeze concentration, the possible viscosity enhancement due to a particular combination of solutes, and the molecular size of the substrate molecule rather than the glass transition process. The Arrhenius equation described the temperature dependence of kinetics both in the liquid state of all the systems studied (r(2) > or = 0.97) and the glassy state of CMC (r(2) = 0.95). A clear break in the Arrhenius plot was observed as the temperature decreased to subfreezing temperatures. The Arrhenius equation could describe the kinetics reasonably well in the rubbery state for fructose and sucrose model systems (r(2) > 0.992). In the case of maltodextrin and CMC, the Arrhenius plots showed a slight curvature followed by a break at the glass transition temperature for CMC. The WLF equation with system-dependent coefficients better described the kinetics in the rubbery state of the CMC and part of the maltodextrin system. A linear relationship between the logarithm of the rate and T - Tg' described the kinetics in the sucrose as well as fructose model systems (r(2) = 0.9928 and 0.993, respectively).

Kinetics of the alkaline phosphatase catalyzed hydrolysis of disodium p-nitrophenyl phosphate: effects of carbohydrate additives, low temperature, and freezing.

The kinetics of the alkaline phosphatase catalyzed hydrolysis of disodium p-nitrphenyl phosphate was studied at 25 degrees C in the presence of the carbohydrates sucrose, fructose, lactose, maltodextrin (DE = 13-17), carboxymethylcellulose (CMC), and CMC-lactose (in 1:1 proportion) at different concentrations and in the presence of sucrose at two different concentrations in a temperature range between 25 and -10 degrees C in subcooled and frozen systems. The objective was to determine whether the reaction is diffusion-controlled, to gain an insight about the factors that determine the diffusion of the reaction species, to understand the mechanism through which the different carbohydrate additives affect the kinetics of the reaction, and to determine the effect of low temperature and freezing on the structural conformation of the enzyme. It was found that the alkaline phosphatase catalyzed hydrolysis of DNPP under the condition studied is at least partially diffusion-controlled. The results also indicate that the diffusion is not controlled by the macroviscosity of the reaction media. The concentration and type of the molecules that constitute the background matrix seem to be the main factors governing the reaction. The results indicate that the different carbohydrates affect the kinetics of the reaction through the excluded volume effect of molecular crowding and decreased substrate and product diffusion rate and not through nonspecific solute effects, which may cause protein denaturation and alteration in enzyme activity. Low temperature does not seem to affect the structural conformation of the enzyme in the temperature range studied, whereas freezing affected the catalytic properties of the enzyme perhaps through its effect on the structural conformation of the enzyme.

Kinetics of the alkaline phosphatase catalyzed hydrolysis of disodium p-nitrophenyl phosphate in frozen model systems.

The alkaline phosphatase catalyzed hydrolysis of disodium-p-nitrophenyl phosphate was studied in four model systems comprising sucrose, maltodextrin, carboxymethylcellulose (CMC), and CMC-lactose in a temperature range of -28 to 20 degrees C. In the maltodextrin and CMC-lactose model systems, the reaction rate decreased to a very low value as the glass transition temperature was approached. In the CMC and CMC-lactose systems with low initial solute concentration, as a consequence of freeze-concentration, a rate maximum around the initial freezing temperature was observed. The Arrhenius equation described the temperature dependence of the reaction rate both in the liquid and the glassy states in all systems studied, while a slightly curved Arrhenius plot was observed in the "rubbery" state of the CMC and CMC-lactose systems. The WLF equation with system-dependent coefficients described the kinetics in the rubbery state of all the model systems except sucrose, excluding the short temperature range where reaction rate enhancement with decreasing temperature was observed.