Examination of the interrelationships between nutrition, environmental sustainability and food-processing: A concept study using model diets.

Recent work has focused on understanding the link between diet quality and environmental impact, however it is also important to consider the role food processing plays in this relationship. Using model meal plans, this paper examines the link between nutrient content, environmental impact, and processing. Four distinct meal plans were considered - 'Healthy', 'Unhealthy', 'Healthy (plant-based)', 'Healthy (plant-based, processed)'. For each a variety of environmental impact, processing and nutritional composition metrics were compared. Alternative healthy eating index (AHEI) score for the Unhealthy diet was significantly lower than the other three diets. The 'Healthy (plant-based)' diet had the highest AHEI score but was not significantly different to the 'Healthy (plant-based, processed)' and 'Healthy' diet scores. The greenhouse gas emissions for the two plant based diets were not significantly different to each other or to the 'Healthy' diet but were significantly lower than the 'Unhealthy' diet. The 'Healthy', 'Unhealthy', and 'Healthy (plant-based)' diets had similar processing specific energy consumption values however, the 'Healthy (plant-based, processed)' diets had significantly greater specific energy consumption. There was no clear link between diet quality and food processing when considered using processing specific energy value. When the number of processes in each diet was estimated, the unhealthier diet had considerably more processes associated with it. Examining the interaction of nutritional quality, environmental impact and processing of diets in this way highlights the complexity of the inter-relationships. Understanding these interactions is necessary to support the transition to healthy diets from sustainable sources.

Recent developments in applications of physical fields for microbial decontamination and enhancing nutritional properties of germinated edible seeds and sprouts: a review.

Germinated edible seeds and sprouts have attracted consumers because of their nutritional values and health benefits. To ensure the microbial safety of the seed and sprout, emerging processing methods involving physical fields (PFs), having the characteristics of high efficiency and environmental safety, are increasingly proposed as effective decontamination processing technologies. This review summarizes recent progress on the application of PFs to germinating edible seeds, including their impact on microbial decontamination and nutritional quality and the associated influencing mechanisms in germination. The effectiveness, application scope, and limitation of the various physical techniques, including ultrasound, microwave, radio frequency, infrared heating, irradiation, pulsed light, plasma, and high-pressure processing, are symmetrically reviewed. Good application potential for improving seed germination and sprout growth is also described for promoting the accumulation of bioactive compounds in sprouts, and subsequently enhancing the antioxidant capacity under favorable PFs processing conditions. Moreover, the challenges and future directions of PFs in the application to germinated edible seeds are finally proposed. This review also attempts to provide an in-depth understanding of the effects of PFs on microbial safety and changes in nutritional properties of germinating edible seeds and a theoretical reference for the future development of PFs in processing safe sprouted seeds.

Roles of physical fields in the extraction of pectin from plant food wastes and byproducts: A systematic review.

Pectin is a naturally occurring hydrocolloid found in the cell wall and middle lamella of many plants and has numerous functional applications in food and other related industries. The type of extraction methods used in production has a strong influence on the structural or physicochemical properties of the resultant pectin and the potential application or market value of the produced pectin. Many conventional extraction methods are well-established and commercially well adopted. However, the increased demand for pectin due to limitations of the existing methods in terms of efficiency and influence on end product quality has been renewed in developing novel techniques or procedures that help to alleviate these problems. In this review paper, a series of strategies involving the application of physical fields, such as acoustic, electromagnetic, electric and mechanical one, are reviewed for potential opportunities to improve the yield and quality attributes of pectin extracted from plant food wastes and byproducts. The extraction mechanism, processing equipment, key operating parameters as well as advantages and disadvantages of each method are systematically reviewed, and findings and conclusions on the potential applications of each method are described. Moreover, the challenges and future directions of physical field assisted extraction (PFAE) of pectin are also discussed to facilitate a better understanding of the complex mechanism in PFAE and optimizing operational parameters. This review may also provide specific theoretical information and practical applications to improve the design and scale up PFAE of pectin.

Improving vitamin D3 stability to environmental and processing stresses using mixed micelles.

Deficiency of vitamin-D is prevalent globally and can lead to negative health consequences. The fat-soluble nature of vitamin-D, coupled with its sensitivity to heat, light and oxygen limits its incorporation into foods. Mixed micelles (MM) have potential to enhance bioavailability of vitamin-D. This study explores the stability of MM to food processing regimes and their ability to protect vitamin-D. Subjecting MM to a range of shearing speeds (8,000-20,500 rpm) and to high pressure processing (600 MPa, 120sec) resulted in no change in MM size (4.1-4.5 nm). MM improved the retention of vitamin-D following exposure to UV-C light, near UV/visible light, and heat treatment. MM suspensions protected vitamin-D over a four week storage period at refrigeration or freezer conditions. Overall MM show potential to protect vitamin-D from degradation encountered in food processing and storage and may be beneficial as a mechanism to fortify foods with vitamin-D.

The impact of emerging domestic and commercial electro-heating technologies on energy consumption and quality parameters of cooked beef.

The purpose of this study was to investigate the effects of e-Cooker® and moderate electric field (MEF) cooking on physical and chemical changes occurring during the cooking of meat. Beef muscle samples (38.86 ± 0.08 g) were cooked in saline solution (0.5% w/w NaCl) to a target temperature of 72 °C, followed by a 2 min holding time. The experimental results revealed that e-Cooker® and MEF significantly reduced the come-up time required to achieve a target temperature of 72 °C to 1.16 ± 0.02 min and 0.86 ± 0.02 min, respectively compared to 14.12 ± 0.55 min in conventional cooking. The colour and instrumental texture of cooked meat by e-Cooker® and MEF systems were not significantly different (P > 0.05) from conventionally cooked ones. Overall, the results obtained demonstrated that e-Cooker® and MEF can be used to cook meat in a shorter time and reasonably low energy input while producing a product which is comparable in quality to conventionally cooked meat.

High-Pressure Processing for the Production of Added-Value Claw Meat from Edible Crab (Cancer pagurus).

High-pressure processing (HPP) in a large-scale industrial unit was explored as a means for producing added-value claw meat products from edible crab (Cancer pagurus). Quality attributes were comparatively evaluated on the meat extracted from pressurized (300 MPa/2 min, 300 MPa/4 min, 500 MPa/2 min) or cooked (92 °C/15 min) chelipeds (i.e., the limb bearing the claw), before and after a thermal in-pack pasteurization (F9010 = 10). Satisfactory meat detachment from the shell was achieved due to HPP-induced cold protein denaturation. Compared to cooked or cooked-pasteurized counterparts, pressurized claws showed significantly higher yield (p < 0.05), which was possibly related to higher intra-myofibrillar water as evidenced by relaxometry data, together with lower volatile nitrogen levels. The polyunsaturated fatty acids content was unaffected, whereas the inactivation of total viable psychrotrophic and mesophilic bacteria increased with treatment pressure and time (1.1-1.9 log10 CFU g-1). Notably, pressurization at 300 MPa for 4 min resulted in meat with no discolorations and, after pasteurization, with high color similarity (ΔE* = 1.2-1.9) to conventionally thermally processed samples. Following further investigations into eating quality and microbiological stability, these HPP conditions could be exploited for producing uncooked ready-to-heat or pasteurized ready-to-eat claw meat products from edible crab.

Monitoring the effect of different microwave extraction parameters on the recovery of polyphenols from shiitake mushrooms: Comparison with hot-water and organic-solvent extractions.

The current study aimed to investigate the effect of different microwave-assisted extraction (MAE) parameters (i.e., particle size of the sample, solid-to-liquid ratio, microwave power, and extraction time) on the total phenolic content (TPC), antioxidant capacity (DPPH and CUPRAC), chlorogenic acid and caffeic acid contents of shiitake mushrooms. All the independent variables affected TPC and antioxidant capacity values. Only the sample particle size had no significant effect on phenolic acid contents. The highest TPC, DPPH, and CUPRAC values were obtained when a particle size of 1.75 mm, solid-to-liquid ratio of 1/40, microwave power of 600 W, and extraction time of 15 min were used. The extracts obtained by MAE were compared with those obtained after hot-water extraction (HWE) and organic-solvent extraction (OSE). Scanning electron microscopy (SEM) confirmed that MAE resulted in cell wall disruption which might be due to an increase in the pressure of the inner part of the cells.

Novel Technologies for Preserving Ricotta Cheese: Effects of Ultraviolet and Near-Ultraviolet-Visible Light.

Ricotta cheese is a potential growth medium for a wide range of microorganisms. The aim of the current study was to investigate the efficacy of ultraviolet (UV-C) and near-ultraviolet-visible light (NUV-vis) in microbial decontamination of ricotta artificially inoculated with Pseudomonas fluorescens. Cheese samples were stored at 4 °C, and microbiological and sensory analyses were performed for 9 days. From the microbiological point of view, control samples became unacceptable after less than 5 days, whereas ricotta treated by both UV-C and NUV-vis light remained acceptable for more than 6 days. Similar effects of UV-C and NUV-vis light were also recorded in terms of sensory quality. The shelf life of the samples subjected to the treatments was thus extended by 50%, suggesting the potential application of UV-C and NUV-vis light for cheese decontamination.

Effect of Pulsed Electric Field Pretreatment on Drying Kinetics, Color, and Texture of Parsnip and Carrot.

The aim of the study was to evaluate the effect of pulsed electric field (PEF) pretreatment on drying kinetics and on color and textural changes in sliced parsnip and carrot. Cell disintegration index measured in parsnips after PEF pretreatment significantly differed from the ones measured for carrots and, consequently, the reduction of the time needed to dry both samples to a final moisture content up to 5% (wet basis). The drying time of the PEF pretreated parsnip was reduced by up to 28% at 70 °C and by up to 21% at 60 °C in carrot, in comparison to untreated samples. The PEF pretreatment influenced the effective diffusivity of water into the samples going from 50 °C to 70 °C: in carrots it ranged between 1.61 × 10-10 and 3.04 × 10-10 (m2 /s), although, in parsnip, it ranged between 1.97 × 10-10 and 3.06 × 10-10 (m2 /s). Also, PEF pretreatment influenced color changes: PEF pretreated dried carrots showed a significant (p < .05) reduction in lightness values (L* ) compared to untreated dried ones, although PEF pretreated parsnip had a significant (p < .05) increase in redness values (a* ). The PEF treatment did not affect the mechanical properties (p > .05) of carrot and parsnip dried at 50 and 60 °C, whereas at 70 °C a significant increase (p < .05) of the force required to cut both root slices was detected. The choice of a PEF pretreatment of foods to be dried should be related to shorten the drying time and to minimize the loss in quality properties mentioned above. PRACTICAL APPLICATION: Dry carrots and parsnip slices can be used as food ingredients for further food preparations but also as healthy snacks, thanks to their health benefits. Pulsed electric field (PEF) resulted to be an effective pretreatment for carrots and parsnips before undergoing convective drying, because it reduced the drying time (up to 28% in parsnip and 21% in carrot slices) and, particularly at mild temperatures (50 to 60 °C), it did not affect the texture properties of both carrot and parsnip. PEF pretreatment of these roots before convective heating can be surely suggested as industrial application.

High intensity light pulses to reduce microbial load in fresh cheese.

The present study focused on the utilisation of High Intensity Light Pulses (HILP) treatment to preserve mozzarella cheese. First, the susceptibility of Pseudomonas fluorescens and Enterobacteriaceae to HILP (fluences from 0·39 to 28·0 J/cm2) in a transparent liquid was evaluated (in-vitro tests). Afterwards, the effects on inoculated mozzarella cheese were also assessed. Then untreated (Control) and HILP treated samples were packaged and stored at 10 °C for 2 weeks. Enterobacteriaceae, Pseudomonas spp. and pH were monitored during storage. In a transparent liquid (in-vitro tests) there was a significant microbial inactivation just with 2 s of treatment. On the inoculated cheese a relevant microbial reduction of about 1 log cycle was observed, according to the exposure to the treatments. For Pseudomonas spp. in particular, in the treated samples, the microbiological acceptability limit (106 cfu/g) was never reached after 2 weeks of refrigerated storage. To sum up, the efficacy of this treatment is very interesting because a microbial reduction was observed in treated samples. HILP treatment is able to control the microbial growth and may be considered a promising way to decontaminate the surface of mozzarella cheese.

One-directional modelling to assess the mechanistic actions of power ultrasound on NaCl diffusion in pork.

A one-directional modelling method for the assessment of the influence of power ultrasound (US) (4-19Wcm-2, 25-40min) on NaCl diffusion in pork is presented. In doing so, the mechanistic actions of US salting in meat are elucidated. Temperature controls (4-21°C) were generated according to each US treatment. NaCl concentration profiles were fitted to Fick's second law, generating the effective NaCl diffusion coefficient (Dseff). Dseff ranged from 1.34×10-10 to 4.01×10-10m2s-1, which is in agreement with the literature. The average Dseff was higher at increased temperature (p<0.05) and US intensity (p<0.01) and a lower Dseff was found with longer US treatment time as an effect of structural changes in the meat (p<0.05). The Dseff was higher at all US intensities than the corresponding temperature control indicating that mass transfer is accelerated by US mechanisms, such as cavitation, independent of temperature effects. This study provides further information on the mechanistic actions of ultrasonic enhanced mass transfer and further proves the potential of power US for the accelerated salting of pork.

The impact of pulsed electric fields and ultrasound on water distribution and loss in mushrooms stalks.

Pulsed electric fields (PEF) and ultrasound (US) are promising innovative technologies with the potential to increase mass transfer when combined with further processes which in turn can provide potential benefits in the recovery of valuable compounds from food by-products. To provide evidence of the mechanism of mass transfer enhancement, the present study assessed the impact of PEF and US treatments, applied individually and in combination, at low and high temperatures, on the tissue microstructure of mushroom stalks. Different indices such as quantitative water redistribution, water loss and qualitative release of compounds were evaluated. The combination of these physical methods demonstrated that PEF redistributed a greater proportion of intracellular water into extracellular spaces than US. However, the application of high temperature treatments alone showed an even greater proportion of intracellular water migration compared to PEF. When PEF was combined with US at low temperatures the difference was not significant.

Light based technologies for microbial inactivation of liquids, bead surfaces and powdered infant formula.

This study evaluates the potential of continuous wave Ultraviolet C light (UV-C) and broad-spectrum intense pulsed light (in this study referred to as High Intensity Light Pulses, HILP) for the inactivation of pathogens of public concern in powdered infant formula (PIF) producers. To achieve this goal a sequential set of experiments were performed, firstly in clear liquid media, secondly on the surface of spherical beads under agitation and, finally in PIF. L. innocua was the most sensitive microorganism to both technologies under all conditions studied with reductions exceeding 4 log10 cycles in PIF. In the clear liquid medium, the maximum tolerance to light was observed for C. sakazakii against UV-C light and for B. subtilis spores against HILP, with a fluence of approximately 17 mJ/cm2 required for a 1 log10 cycle inactivation (D value) of each species. In PIF it was possible to inactivate >99% of the vegetative cell populations by HILP with a fluence of 199 mJ/cm2 and of B. subtilis spores by doubling the fluence. By contrast, for UV-C treatments a fluence of 2853 mJ/cm2 was needed for 99.9% reduction of C. sakazakii, which was the most light-resistant microorganism to UV-C. Results here obtained clearly show the potential for light-based interventions to improve PIF microbiological safety.

Quality attributes and retention of vitamin E in reduced salt chicken sausages fortified with vitamin E.

The effect of salt reduction and vitamin E (α-tocopherol) fortification, at a level in excess of that required for a European Food Safety Authority (EFSA) health claim, on the quality of chicken sausages was investigated. Four formulations of chicken sausages were prepared: C (control, 1.3% NaCl, 0 mg/kg added α-tocopherol), L (low salt, 0.47% NaCl, 0 mg/kg added α-tocopherol), CE (1.3% NaCl, 200 mg/kg added α-tocopherol), LE (0.47% NaCl, 200 mg/kg added α-tocopherol). Salt or α-tocopherol level did not significantly affect the fat content, protein content, moisture content, lipid oxidation, microbial growth, cook loss or texture profile analysis values of raw or cooked sausages. There was a significant effect of salt level on the ash content of raw and cooked sausages. Colour of cooked sausages was affected by salt reduction, with fried low salt sausages being darker and yellower than control, while grilled low salt sausages were lighter and redder than control. Cooking and storage did not significantly affect α-tocopherol retention, and enough was retained to meet both the EFSA nutrient and health claims. The sensory properties of the sausages were unaffected by the reduction in salt, and by fortification with α-tocopherol.

An assessment of the impact of pulsed electric fields processing factors on oxidation, color, texture, and sensory attributes of turkey breast meat.

Pulsed electric fields (PEF) is a novel nonthermal technology that has the potential to cause physical disruption to muscle tissue which in turn could alter the sensorial aspects of meat in both a positive (e.g., enhanced tenderization) and a negative way (e.g., off-flavor development). If there is a risk of off-flavor development it should be identified prior to embarking on an extensive investigation on PEF in meat tenderization and turkey meat was chosen for this purpose as it is particularly prone to oxidation. The objective of this study was to investigate the effect of various PEF treatments on the quality attributes of turkey breast meat. Turkey breast meat obtained 1 d postslaughter was treated in a batch PEF chamber with increasing electric field strength up to 3 kV/cm and analyzed for lipid oxidation by thiobarbituric acid reactive substances assay (TBARS) with up to 5 d storage at 4°C in aerobic conditions. In a separate experiment, turkey breast meat samples were exposed to PEF under various combinations of pulse number, frequency, and voltage. Following PEF treatments weight loss, cook loss, lipid oxidation, texture, and color were assessed by instrumental methods. A sensory analysis was also performed to determine consumer acceptability for color, texture, and odor of the samples. Lipid oxidation in all PEF-treated samples progressed at the same rate with storage as the untreated samples and was not found to be significantly different to the control. Under the conditions examined PEF treatments did not induce differences in instrumentally measured weight loss, cook loss, lipid oxidation, texture, and color (raw and cooked) either on fresh or frozen samples. However, the sensory evaluation suggested that panelists could detect slight differences between the PEF-treated samples and the controls in terms of texture and odor.

Effect of pulsed electric field treatments at various stages during conditioning on quality attributes of beef longissimus thoracis et lumborum muscle.

Beef longissimus thoracis et lumborum (LTL) muscle was used to evaluate the effect of PEF treatments (1.4 kV/cm, 10 Hz, 20 µs, 300 and 600 pulses) on meat quality attributes (weight loss, colour, cook loss and texture) and its evolution at various stages during ageing (2, 10, 18 and 26 days post-mortem). The length of meat ageing before and after PEF application exerted no influence on weight loss, colour and cook loss. Results also demonstrated that PEF treatments applied at different times post-mortem (2, 10, 18 and 26 days) showed a tendency towards reducing toughness of beef samples but that the application of PEF did not affect the tenderization process provided by ageing itself. 60% of the sensory panellists scored PEF treated samples as tender (≥6.0 points out of 9.0) whereas only 27.5% did so for untreated samples.

Optimization of pulsed electric field pre-treatments to enhance health-promoting glucosinolates in broccoli flowers and stalk.

BACKGROUND: The effect of pulsed electric field (PEF) treatment variables (electric field strength and treatment time) on the glucosinolate content of broccoli flowers and stalks was evaluated. Samples were subjected to electric field strengths from 1 to 4 kV cm(-1) and treatment times from 50 to 1000 µs at 5 Hz. RESULTS: Data fitted significantly (P < 0.0014) the proposed second-order response functions. The results showed that PEF combined treatment conditions of 4 kV cm(-1) for 525 and 1000 µs were optimal to maximize glucosinolate levels in broccoli flowers (ranging from 187.1 to 212.5%) and stalks (ranging from 110.6 to 203.0%) respectively. The predicted values from the developed quadratic polynomial equation were in close agreement with the actual experimental values, with low average mean deviations (E%) ranging from 0.59 to 8.80%. CONCLUSION: The use of PEF processing at moderate conditions could be a suitable method to stimulate production of broccoli with high health-promoting glucosinolate content.

Observations on the water distribution and extractable sugar content in carrot slices after pulsed electric field treatment.

The impact of pulsed electric field (PEF) processing conditions on the distribution of water in carrot tissue and extractability of soluble sugars from carrot slices was studied. Time domain NMR relaxometry was used to investigate the water proton mobility in PEF-treated carrot samples. Three distinct transverse relaxation peaks were observed in untreated carrots. After PEF treatment only two slightly-overlapping peaks were found; these were attributed to water present in the cytoplasm and vacuole of carrot xylem and phloem tissues. This post-treatment observation indicated an increase in water permeability of tissues and/or a loss of integrity in the tonoplast. In general, the stronger the electric field applied, the lower the area representing transverse relaxation (T2) values irrespective of treatment duration. Moreover an increase in sucrose, ß- and α-glucose and fructose concentrations of carrot slice extracts after PEF treatment suggested increases in both cell wall and vacuole permeability as a result of exposure to pulsed electric fields.

The effect of salt and fibre direction on water dynamics, distribution and mobility in pork muscle: a low field NMR study.

The effect of salt concentration and fibre orientation on water within the meat matrix was investigated by low-field nuclear magnetic resonance (LF-NMR), water-binding capacity (WBC), diffusion studies and histological analysis. Pork M. longissimus thoracis et lumborum samples were cured with 5.7, 15.3 or 26.3% w/w NaCl at a parallel or perpendicular fibre direction. NMR transverse (T2) relaxation identified three water components (T2b, T21 and T22) which all exhibited characteristics correlated to WBC. Results indicated that T2b increases with increasing NaCl concentration. Increasing intra-myofibrillar water and decreasing extra-myofibrillar water resulted in the highest WBC. Water diffused more quickly into the extra-myofibrillar space in samples cured at a parallel fibre direction. This water remained loosely bound in samples cured with the saturated solution (26.3% w/w NaCl) leading to decreased WBC. This study provides further information on water binding within the meat matrix by applying the results of LF-NMR to traditional water-binding theories.

An assessment of the effect of pulsed electrical fields on tenderness and selected quality attributes of post rigour beef muscle.

The effect of conventional and PEF treatment (electric field strength: 1.1-2.8 kV cm(-1); energy density: 12.7-226 kJ/kg), frequency (5-200 Hz) and pulse number (152-300) on selected quality attributes of beef Semitendinosus (ST) was investigated. While PEF is viewed as a "non-thermal" treatment, it can induce moderate temperature rises (∆T). To eliminate any potential effect of mild temperature increases, PEF treated samples were compared to conventionally treated (water bath) samples exposed to similar temperature rises (5-35 °C) and handling conditions. Weight loss, conductivity, water holding properties and particle sizes were measured pre- and post-treatment. PEF treatment that induced a ∆T of 22 °C significantly (P<0.05) affected weight loss of samples post treatment. Particle size analysis of the extracted myofibrils showed PEF significantly (P<0.05) affected the myofibrils while weight loss results suggest that PEF treatment may have led to slight changes in the cell membrane leading to more water loss. However, instrumental texture was unaffected by the treatments applied.