Modified-atmosphere packaging of hen table eggs: Effects on pathogen and spoilage bacteria

Abstract As part of a more comprehensive research activity on the use of modified-atmosphere packaging for the improvement of quality and functional properties of table eggs, the effects of air, 100% CO2, and 100% O2 packaging were also evaluated on the survival of experimentally inoculated pathogen bacteria (Salmonella Enteritidis, Escherichia coli, and Listeria monocytogenes) as well as on spoilage bacteria (total aerobic mesophilic bacteria) on table eggs during 30 d of storage at 4, 25, and 37°C by colony count method. In general, temperatures played a major role, rather than gasses, in influencing the bacterial survival. In particular, the lowest microbial loads were registered at 4°C on E. coli and spoilage bacteria, whereas 37°C was the best storage temperature to avoid the psychrotropic microorganism L. monocytogenes development regardless of the gas used. One hundred percent CO2 packaging, in association with a low storage temperature (4°C), had a significant positive effect in reducing Salmonella loads. On eggs inoculated with L. monocytogenes and stored at 4°C as well as on eggs containing only spoilage bacteria and stored at 25°C, 100% CO2 resulted the best gas in comparison with air and O2. One hundred percent CO2 packaging showed no negative effect on pathogen survival compared with air. Although further improvements are required to control RH within packaging to limit bacteria growth/survival, in view of the positive effects of CO2 packaging on quality traits of table eggs, 100% CO2 packaging might represent a promising innovative technique for the maintenance of egg characteristics during transport, retail, and domestic storage

Quality and stability of different seafood products treated with high hydrostatic pressure (HPP) intended for raw consumption

The consumption of raw fish has rapidly increased in recent years, but being a highly perishable product, it is characterised by a very short microbiological shelf life. High hydrostatic pressure (HPP) processing is a non -thermal technology has emerged recently as a promising alternative to thermal processing for food pasteurization capable of maintaining fresh-like characteristics and nutritional value. However, the induced changes in product quality should be assessed carefully. The present research aimed to investigate the effect of HPP on different seafood products, namely grey mullet, tiger prawn and rose shrimp, intended for raw consumption. Three pres-sure levels (400, 500 and 600 MPa) were applied for 10 min. During refrigerated storage, microbiological quality, chemical parameters, colour and texture and fat oxidation were analysed. Results showed that the application of lower pressure was able to inactivate E. coli, pseudomonas and/or positive coagulase staphylococci; however, they were able to recover during storage. In addition, the application of 600-MPa pressure extended the microbio-logical shelf life by up to 30 days. For all samples, general whitening occurred while the texture was affected in a different way for the three considered species. Fat oxidation was only minimally affected and remained quite low during storage

Modified atmosphere packaging of hen table eggs: Effects on functional properties of albumen

The aim of this study was to compare technological properties (gel hardness, foam drainage, and meringue crispness) of albumen of nonpacked table eggs (control) with those of eggs packed in high-barrier plastic pouches with 3 modified atmosphere packaging (MAP) conditions (air, 100% N2, and 100% CO2) during 28 d of storage at 25°C. The values of gel hardness for the control sample showed an increasing trend, demonstrating the highest values throughout the experiment duration compared with the other samples. This behavior was probably attributable to the pH increase detected only for this sample during storage (from 8.82 ± 0.06 for fresh egg to 9.96 ± 0.06 at the end of the experiment). Air and N2 samples showed constant and similar hardness values during storage. The hardness of coagulated albumen showed a strict correlation with raw albumen pH (r2 = 0.929; P < 0.001). Other than reducing albumen pH during storage, MAP with CO2 caused the formation of a soft and puffy coagulum with very low hardness, reaching the lowest value of 1.26 ± 0.38 N after 4 d of storage, that slowly increased to 2.11 ± 0.49 N at the end of the experiment. Foam stability decreased during storage for all samples, but CO2 eggs showed a significantly (P < 0.05) higher foam stability than fresh eggs until 15 d, reaching values similar to those of the other samples only at the end of the storage time. Packing eggs in CO2 promoted an improvement of meringue crispness. The application of this atmosphere could ameliorate the quality characteristics of albumen-based food products. Commercially, CO2 MAP could provide an albumen-based ingredient tailored to maximize the characteristics needed in the final product (e.g., fresh shell eggs special for meringue preparation) that could give an added value to the product

Kiwifruit waste valorisation through innovative snack development

Currently, in the case of kiwifruits, those fruit with a weight lower than 65 g are considered waste. The production of dried snacks with high nutritional functionality could be a valid alternative to use the kiwifruit waste, with positive economic impact on the entire production chain. Therefore, the aim of this work was to evaluate the effect of pulsed electric field – PEF (200 V cm-1) and/or osmotic dehydration – OD (trehalose at 40%) pre-drying treatments on drying kinetics at 50, 60, and 70°C, and on colour and nutritional properties (vitamin C and antioxidant compounds) of ‘Jintao’ (yellow-fleshed) kiwifruit snacks. At every temperature, the PEF treated snacks showed the highest drying rate. Moreover, PEF treatment appeared to be a valid innovative alternative for the production of fruit snacks with high nutritional quality. A better retention of vitamin C and antioxidant compounds was obtained in dried yellow kiwifruit subjected to PEF treatment

The use of sodium bicarbonate for marination of broiler breast meat

This study aimed at evaluating marination performances and effect on meat quality traits of sodium bicarbonate, used alone or in combination with sodium chloride, when compared with sodium trypolyphosphate by using advanced analytical tools including low-field nuclear magnetic resonance (LF-NMR) and differential scanning calorimetry (DSC). A total of 140 samples (cylindrical shape of 1×4 cm size) were obtained from a batch of 24h post mortem broiler breast meat (Ross 708, females, 47 day-old). Six of the groups were used for subsequent marination treatments, while the last group was kept as non-marinated control (C). Samples were subjected to vacuum tumbling in a special equipped laboratory rotary evaporator with a 12% (w/w) water:meat ratio using 6 marinade solutions: 7.7% (w/w) NaCl (S); 2.3% Na4O7P2 (w/w) (P); 2.3% (w/w) NaHCO3 (B); 7.7% (w/w) NaCl and 2.3% Na4O7P2 (w/w) (SP); 7.7% (w/w) NaCl and 2.3% (w/w) NaHCO3 (SB); 7.7% (w/w) NaCl, 2.3% Na4O7P2 (w/w) and 2.3% (w/w) NaHCO3 (SPB). Samples marinated with bicarbonate alone or in combination (B, SB and SPB) significantly increased (P<0.05) meat pH by approximately 0.7 units compared to the control, whilst phosphate alone or in combination with salt increased (P<0.05) the pH by 0.2 units. Combination containing all ingredients (SPB) produced the highest marinade performances, however sodium bicarbonate with salt (SB) was able to guarantee a better marinade uptake and water retention ability in respect to phosphates (SP). According to LR-NMR, the combined use of bicarbonate and/or phosphate with sodium chloride determined a remarkable increase of proportion of entrapped water into myofibrillar spaces, while extra-myofibrillar water fraction was not modified. Moreover water gain following marination does not correspond to an increase of freezable water amount as detected by DSC. In conclusion, bicarbonate is a very promising marinating agent and it can be exploited to develop processed poultry products with no added phosphates in order to match the request to avoid the nutritional drawbacks recently indicated with the use of phosphates

Gaping of pectoralis minor muscles: magnitude and characterization of an emerging quality issue in broilers

Recently, a certain number of broiler abattoirs located in different Countries around the World have signaled an emerging quality issue termed "gaping" because of the separation of the fiber bundles affecting the external portion of the bipinnate pectoralis minor muscle. Thus, after defining the criteria to classify the muscles as Normal (NORM), Moderate (MOD), or Severe (SEV) cases, the incidence of gaping under commercial conditions was assessed on a total of 8,600 P. minor obtained from broiler chickens belonging to 43 flocks during a 6-mo period. Then, a total of 180 P. minor were selected based on previously defined criteria to evaluate the main quality traits (pH, color, water-holding/-binding capacity and tenderness), proximate composition, water mobility, and thermal properties as well as metabolic profile through 1H-Nuclear Magnetic Resonance spectroscopy. The average incidence of gaping defect was found to be 16.8% (8.8 and 8.0% MOD and SEV cases, respectively). As for the main quality traits, a reduction in ultimate pH was observed as the severity of the gaping defect increased, with SEV muscles displaying significantly lower values in comparison with NORM (5.96 vs. 6.02; P < 0.01), while MOD showed intermediate values (5.99). Concurrently, if compared with their NORM counterpart, MOD and SEV exhibited higher lightness (53.6 and 54.2 vs. 51.8; P < 0.01) coupled with higher (P < 0.05) cooking losses and longer (P < 0.05) transversal relaxation time of extra-myofibrillar water fraction. Overall, no significant differences were found concerning proximate composition and thermal properties. With regard to the metabolic profile, a significantly lower (P < 0.001) glutamine concentration was found in MOD and SEV muscles that, concurrently, revealed significant (P < 0.05) variations in the metabolites involved in energy-generating pathways. Overall, these findings evidenced that the gaping defect affecting broilers' P. minor muscles have strong similarities with the pale-soft-exudative condition previously described in poultry and likely results from the biochemical processes taking place during the post-mortem conversion of muscle to meat

Innovative non-thermal technologies for recovery and valorization of value-added products from crustacean processing by-products—an opportunity for a circular economy approach

The crustacean processing industry has experienced significant growth over recent decades resulting in the production of a great number of by-products. Crustacean by-products contain several valuable components such as proteins, lipids, and carotenoids, especially astaxanthin and chitin. When isolated, these valuable compounds are characterized by bioactivities such as antimicrobial, antioxidant, and anti-cancer ones, and that could be used as nutraceutical ingredients or additives in the food, pharmaceutical, and cosmetic industries. Different innovative non-thermal technologies have appeared as promising, safe, and efficient tools to recover these valuable compounds. This review aims at providing a summary of the main compounds that can be extracted from crustacean by-products, and of the results obtained by applying the main innovative nonthermal processes for recovering such high-value products. Moreover, from the perspective of the circular economy approach, specific case studies on some current applications of the recovered compounds in the seafood industry are presented. The extraction of valuable components from crustacean by-products, combined with the development of novel technological strategies aimed at their recovery and purification, will allow for important results related to the long-term sustainability of the seafood industry to be obtained. Furthermore, the reuse of extracted components in seafood products is an interesting strategy to increase the value of the seafood sector overall. However, to date, there are limited industrial applications for this promising approach

Effect of plasma activated water (PAW) on rocket leaves decontamination and nutritional value

Plasma Activated Water (PAW) obtained by exposing water to cold atmospheric pressure plasma, has recently emerged as a promising alternative for food decontamination, compared to the use of traditional chemical sanitizers. The aim of the study was to evaluate the efficacy of PAW treatments for rocket salad decontamination. Washing with PAW for 2, 5, 10 and 20 min was assessed against different endogenous spoilage microorganisms and compared to untreated water and hypochlorite solution. The chemical composition of PAW as a function of treatment and delay time was characterized and the effect on product quality and nutritional parameters was evaluated. Results showed that PAW allowed an average reduction of 1.7–3 Log CFU/g for total mesophilic and psychrotrophic bacteria and Enterobacteriaceae following 2–5 min washing with minimal variation of qualitative and nutritional parameters. Overall, experimental results highlighted the potentiality of PAW treatments as a promising alternative to chlorine having the advantage of a minor adverse impact on environment and consumers' health. Industrial relevance: To meet consumers demand, the minimally processed fruit and vegetable industry needs to find sustainable solutions as alternative to the use of traditional chemical sanitizers that allow to increase product shelf-life and preserve safety, qualitative and nutritional characteristics. Plasma activated water represents a promising strategy for food decontamination, but its effects on foods have been only limitedly investigated. The present research is the first study on the use of plasma activated water on fresh rocket leaves, providing new and important information on microbial inactivation and quality of the fresh cut product

Exploring metabolic responses of potato tissue induced by electric pulses

In this study, we investigated the metabolic responses of potato tissue induced by pulsed electric field (PEF). Potato tissue was subjected to field strengths ranging from 30 to 500 V/cm, with a single rectangular pulse of 10 μs, 100 μs, or 1 ms. Metabolic responses were monitored using isothermal calorimetry, changes on electrical resistance during the delivery of the pulse, as well as impedance measurements. Our results show that the metabolic response involves oxygen consuming pathways as well as other unidentified events that are shown to be insensitive to metabolic inhibitors such as KCN and sodium azide. The metabolic response is strongly dependent on pulsing conditions and is independent of the total permeabilization achieved by the pulse. Evidence shows that calorimetry is a simple and powerful method for exploring conditions for metabolic stimulation, providing information on metabolic responses that can not be obtained from electrical measurements. This study set the basis for further investigations on defense-related consequences of PEF-induced stress.Sparbanksstiftelsen Färs & Frosta (Sweden).Fundação para a Ciência e a Tecnologia (FCT).Lund University (Sweden).Department of Cell and Organism Biology; Department of Plant Biochemistry