Tailor-made packaging strategies of fresh pork belly with different fat content: Enhancing shelf life while minimizing environmental impact.

Pork belly is a meat cut valued for its rich flavour and texture, attributed to its high fat content, which also makes it susceptible to oxidation. Therefore, meat producers and processors must carefully select packaging options to maximise shelf life while meeting consumer preferences. This study aimed to develop customised packaging strategies for sliced pork belly with varying fat content to extend shelf life while minimizing environmental impact. The research compared three packaging solutions: modified atmosphere packaging (MAP1: 70:30% O2:CO2, MAP2: 30:40:30% O2:CO2:N2) and vacuum skin packaging (VSP) for pork bellies with low (LF: 16.07 ± 1.87%), medium (MF: 37.39 ± 4.41%), and high fat content (HF: 57.57 ± 2.36%). Samples packaged in VSP exhibited the longest shelf life (13-14 days) with lower purge and reduced fat and colour oxidation compared to MAP-packaged samples for all studied belly types. Nonetheless, the impact of MAP on shelf life depended on the belly type. HF bellies, with lower proportions of unsaturated fatty acids, showed less purge, and greater colour and fat stability, resulting in a longer shelf life compared to LF and MF bellies. LF and MF bellies in MAP2 showed the shortest shelf life (around 6 days), followed by LF and MF in MAP1 (around 7-8 days). Life Cycle Assessment indicated VSP generally as the most environmentally favourable option for LF and MF bellies, whereas for HF bellies, the choice among the three packaging solutions depended on the specific impact category under consideration.

The role of carcass processing (hot vs. cold boning) on pork belly morphological and mechanical characteristics.

This study assessed the effect of boning processing method (hot vs. cold) on pork belly morphological and mechanical traits and the evolution of these traits during refrigerated storage postmortem (PM). A total of 14 crossbred pigs were slaughtered and their carcasses and bellies processed under two conditions: hot boning (n = 14, right sides of carcasses cut immediately after slaughter) and cold boning (n = 14, left sides of carcasses cut 24 h PM). Morphological and mechanical evaluations were made at 1-, 5-, 24- and 48-h PM on the hot-boned bellies, and at 24 and 48 h on the cold-boned ones. Compared to the cold-boned bellies, the hot-boned ones were shorter, wider and thicker (P < 0.01), with greater firmness (flop distance and angle) (P < 0.001) and cohesiveness (skin-fat separation) (P < 0.05 in the dorsal and central sections). At 48 h PM, hot-boned bellies had a thicker skin (P < 0.001) and softer subcutaneous fat in the dorsal-cranial and central sections (finger scores and compression textural test) (P < 0.05). Morphological and mechanical traits for hot-boned bellies confirmed an intense shortening and hardening (increased firmness and cohesiveness), and a slight yield loss from 1 to 24 h PM. From 24 to 48 h PM, there was a certain flattening in hot-boned bellies that was associated with a slight softening (reduced firmness). Although a larger sample may be needed to corroborate these findings, they demonstrate the impact of carcass processing method and refrigerated storage time on belly quality. This may be useful for the pork industry for obtaining the desired type of belly.

The effect of immunocastration of male and female Duroc pigs on the morphological, mechanical and compositional characteristics of pork belly.

Pork belly is an important and heterogeneous cut, characterized by its fat content. Immunocastration is an alternative to surgical castration that can modify the composition of carcasses and cuts and it can affect at its processing. This work compares the morphological, mechanical and compositional characteristics of pork belly of (1) pure Duroc pigs from surgically castrated males (CM), entire females (EF) and immunocastrated females (IF), and (2) Duroc crossbreed pigs from immunocastrated males (IM) and entire males (EM). Two trials were carried out: Trial 1, in which 36 bellies were evaluated, 12 from each sexual type, CM, EF and IF; and Trial 2, where 30 bellies were used, 15 from each sexual type, IM and EM. Results show few differences in bellies from EF and IF, while those from CM were fatter and firmer and with lower polyunsaturated fat. Bellies from IM were longer and firmer than those from EM, and their skin was thinner. IM bellies had higher saturated and lower polyunsaturated fat than those from EM. To conclude, the sex of the pigs affects belly characteristics and this could be a criterion for determining the destination of the bellies in the cutting plant. Immunocastration of pure Duroc females had a lower effect on the belly characteristics when compared to those from entire females, but some differences could be found in the fat distribution. Immunocastration of Duroc crossbred males produces firmer and thicker bellies, with a thinner skin, that could be advantageous for slicing and further processing.

Poly Lactic Acid (PLA) Nanocomposites: Effect of Inorganic Nanoparticles Reinforcement on Its Performance and Food Packaging Applications.

Poly lactic acid (PLA) is a compostable, as well as recyclable, sustainable, versatile and environmentally friendly alternative, because the monomer of PLA-lactide (LA) is extracted from natural sources. PLA's techno-functional properties are fairly similar to fossil-based polymers; however, in pristine state, its brittleness and delicacy during processing pose challenges to its potential exploitation in diverse food packaging applications. PLA is, therefore, re-engineered to improve its thermal, rheological, barrier and mechanical properties through nanoparticle (NP) reinforcement. This review summarises the studies on PLA-based nanocomposites (PLA NCs) developed by reinforcing inorganic metal/metallic oxide, graphite and silica-based nanoparticles (NPs) that exhibit remarkable improvement in terms of storage modulus, tensile strength, crystallinity, glass transition temperature (Tg) value, antimicrobial property and a decrease in water vapour and oxygen permeability when compared with the pristine PLA films. This review has also discussed the regulations around the use of metal oxide-based NPs in food packaging, PLA NC biodegradability and their applications in food systems. The industrial acceptance of NCs shows highly promising perspectives for the replacement of traditional petrochemical-based polymers currently being used for food packaging.

Co-extruded alginate as an alternative to collagen casings in the production of dry-fermented sausages: Impact of coating composition.

The performance of co-extruded alginate coatings containing no extra additives (A), polyglycerol esters of fatty acids (EA), or pea protein (PA) was assessed as an alternative to collagen casings (C) for the manufacturing of dry-fermented sausages (fuet) with no inoculation of moulds and without a fermentation step (NMNF) and fuet inoculated with Penicillium candidum and fermented (MF). Stuffing into collagen casings resulted in slower sausage drying kinetics compared with alginate coating. No significant differences in aw were observed among the studied casing types for NMNF and MF fuets and for the evolution of the technological and spoilage microorganisms. Fuets coated with A, EA, and PA showed lower pH values than fuets stuffed in collagen casings. No significant differences on sensory properties between casing types were observed. Therefore, alginate coatings would be a feasible alternative to collagen casing from a technological and safety point of view.

Synthesis of Polylactic Acid Initiated through Biobased Antioxidants: Towards Intrinsically Active Food Packaging.

Polylactide (PLA)-based polymers, functionalized with biobased antioxidants, were synthesized, to develop an intrinsically active, biobased and potentially biodegradable material for food packaging applications. To achieve this result, phenolic antioxidants were exploited as initiators in the ring opening polymerization of l-lactide. The molecular weight, thermal properties and in vitro radical scavenging activity of the polymers obtained were compared with the ones of a PLA Natureworks 4043D, commonly used for flexible food packaging applications. The most promising synthesized polymer, bearing vanillyl alcohol as initiator (PLA-VA), was evaluated for active food packaging applications. Packaging with PLA-VA films reduced color and fat oxidation of salami during its shelf life.

Active Packaging Applications for Food.

The traditional role of food packaging is continuing to evolve in response to changing market needs. Current drivers such as consumer's demand for safer, "healthier," and higher-quality foods, ideally with a long shelf-life; the demand for convenient and transparent packaging, and the preference for more sustainable packaging materials, have led to the development of new packaging technologies, such as active packaging (AP). As defined in the European regulation (EC) No 450/2009, AP systems are designed to "deliberately incorporate components that would release or absorb substances into or from the packaged food or the environment surrounding the food." Active packaging materials are thereby "intended to extend the shelf-life or to maintain or improve the condition of packaged food." Although extensive research on AP technologies is being undertaken, many of these technologies have not yet been implemented successfully in commercial food packaging systems. Broad communication of their benefits in food product applications will facilitate the successful development and market introduction. In this review, an overview of AP technologies, such as antimicrobial, antioxidant or carbon dioxide-releasing systems, and systems absorbing oxygen, moisture or ethylene, is provided, and, in particular, scientific publications illustrating the benefits of such technologies for specific food products are reviewed. Furthermore, the challenges in applying such AP technologies to food systems and the anticipated direction of future developments are discussed. This review will provide food and packaging scientists with a thorough understanding of the benefits of AP technologies when applied to specific foods and hence can assist in accelerating commercial adoption.

Active and intelligent packaging systems for a modern society.

Active and intelligent packaging systems are continuously evolving in response to growing challenges from a modern society. This article reviews: (1) the different categories of active and intelligent packaging concepts and currently available commercial applications, (2) latest packaging research trends and innovations, and (3) the growth perspectives of the active and intelligent packaging market. Active packaging aiming at extending shelf life or improving safety while maintaining quality is progressing towards the incorporation of natural active agents into more sustainable packaging materials. Intelligent packaging systems which monitor the condition of the packed food or its environment are progressing towards more cost-effective, convenient and integrated systems to provide innovative packaging solutions. Market growth is expected for active packaging with leading shares for moisture absorbers, oxygen scavengers, microwave susceptors and antimicrobial packaging. The market for intelligent packaging is also promising with strong gains for time-temperature indicator labels and advancements in the integration of intelligent concepts into packaging materials.

High pressure induced changes in beef muscle proteome: correlation with quality parameters.

The relationship between pressure induced changes on individual proteins and selected quality parameters in bovine longissimus thoracis et lumborum (LTL) muscle was studied. Pressures ranging from 200 to 600 MPa at 20°C were used. High pressure processing (HPP) at pressures above 200 MPa induced strong modifications of protein solubility, meat colour and water holding capacity (WHC). The protein profiles of non-treated and pressure treated meat were observed using two dimensional electrophoresis. Proteins showing significant differences in abundance among treatments were identified by mass spectrometry. Pressure levels above 200 MPa strongly modified bovine LTL proteome with main effects being insolubilisation of sarcoplasmic proteins and solubilisation of myofibrillar proteins. Sarcoplasmic proteins were more susceptible to HPP effects than myofibrillar. Individual protein changes were significantly correlated with protein solubility, L, b and WHC, providing further insights into the mechanistic processes underlying HPP influence on quality and providing the basis for the future development of protein markers to assess the quality of processed meats.

Consumer acceptance of high pressure processed beef-based chilled ready meals: the mediating role of food-related lifestyle factors.

The aim of this research was to investigate the effects of high pressure processing (HPP) on consumer acceptance for chilled ready meals manufactured using a low-value beef cut. Three hundred consumers evaluated chilled ready meals subjected to 4 pressure treatments and a non-treated control monadically on a 9-point scale for liking for beef tenderness and juiciness, overall flavour, overall liking, and purchase intent. Data were also collected on consumers' food consumption patterns, their attitudes towards food by means of the reduced food-related lifestyle (FRL) instrument, and socio-demographics. The results indicated that a pressure treatment of 200 MPa was acceptable to most consumers. K-means cluster analysis identified 4 consumer groups with similar preferences, and the optimal pressure treatments acceptable to specific consumer groups were identified for those firms that would wish to target attitudinally differentiated consumer segments.

Influence of HPP conditions on selected beef quality attributes and their stability during chilled storage.

The aim of this work was to determine the effects of combined pressure and temperature treatments on beef quality attributes after processing and during chilled storage. Beef M. pectoralis profundus samples were pressurised at 400 and 600 MPa at 35, 45 and 55°C and compared with non-treated (NT) and oven cooked samples. High pressure processing (HPP) at higher temperatures (55°C) resulted in lower Warner Bratzler Shear Force (WBSF) and cook loss values than processing at 35°C. Thiobarbituric acid reactive substances (TBARS) values of pressurised samples were lower than cooked samples after processing and throughout refrigerated storage. An increase (p<0.001) in the omega 6/omega 3 (n6/n3) fatty acid ratio was found when pressure-temperature treatments were compared to raw samples, however, oven cooked samples presented the highest n6/n3 ratio among all of the treatments examined. The reported results show that HPP alters meat quality to a lesser extent than conventional cooking, thereby minimising the processing impact.

High pressure induced changes on sarcoplasmic protein fraction and quality indicators.

The combined effect of pressure and mild temperature treatments on bovine sarcoplasmic proteins and quality parameters was assessed. M. longissimus dorsi samples were pressurised in a range of 200-600 MPa and 10-30 degrees C. High Pressure Processing (HPP) induced a reduction of protein solubility (p<0.001) compared to non-treated controls (NT), more pronounced above 200 MPa. HPP at pressures higher than 200 MPa induced a strong modification (p<0.001) of meat colour and a reduction of water holding capacity (WHC). SDS-PAGE analysis demonstrated that HPP significantly modified the composition of the sarcoplasmic protein fraction. The pressurisation temperature mainly affected protein solubility and colour; a smaller effect was observed on protein profiles. Significant correlations (p<0.001) between sarcoplasmic protein solubility and both expressible moisture (r=-0.78) and colour parameters (r=-0.81 to -0.91) suggest that pressure induced denaturation of sarcoplasmic proteins could influence to some extent WHC and colour modifications of beef. Changes in protein band intensities were also significantly correlated with protein solubility, meat lightness and expressible moisture. These results describe the changes induced by HPP on sarcoplasmic proteins and confirm a relationship between modification of the sarcoplasmic protein fraction and alteration of meat quality characteristics.

Physical performance of biodegradable films intended for antimicrobial food packaging.

Antimicrobial films were prepared by including enterocins to alginate, polyvinyl alcohol (PVOH), and zein films. The physical performance of the films was assessed by measuring color, microstructure (SEM), water vapor permeability (WVP), and tensile properties. All studied biopolymers showed poor WVP and limited tensile properties. PVOH showed the best performance exhibiting the lowest WVP values, higher tensile properties, and flexibility among studied biopolymers. SEM of antimicrobial films showed increased presence of voids and pores as a consequence of enterocin addition. However, changes in microstructure did not disturb WVP of films. Moreover, enterocin-containing films showed slight improvement compared to control films. Addition of enterocins to PVOH films had a plasticizing effect, by reducing its tensile strength and increasing the strain at break. The presence of enterocins had an important effect on tensile properties of zein films by significantly reducing its brittleness. Addition of enterocins, thus, proved not to disturb the physical performance of studied biopolymers. Development of new antimicrobial biodegradable packaging materials may contribute to improving food safety while reducing environmental impact derived from packaging waste. Practical Application: Development of new antimicrobial biodegradable packaging materials may contribute to improving food safety while reducing environmental impact derived from packaging waste.

High-pressure processing and antimicrobial biodegradable packaging to control Listeria monocytogenes during storage of cooked ham.

The efficiency of combining high-pressure processing (HPP) and active packaging technologies to control Listeria monocytogenes growth during the shelf life of artificially inoculated cooked ham was assessed. Three lots of cooked ham were prepared: control, packaging with alginate films, and packaging with antimicrobial alginate films containing enterocins. After packaging, half of the samples were pressurized. Sliced cooked ham stored at 6 degrees C experienced a quick growth of L. monocytogenes. Both antimicrobial packaging and pressurization delayed the growth of the pathogen. However, at 6 degrees C the combination of antimicrobial packaging and HPP was necessary to achieve a reduction of inoculated levels without recovery during 60 days of storage. Further storage at 6 degrees C of pressurized antimicrobial packed cooked ham resulted in L. monocytogenes levels below the detection limit (day 90). On the other hand, storage at 1 degrees C controlled the growth of the pathogen until day 39 in non-pressurized ham, while antimicrobial packaging and storage at 1 degrees C exerted a bacteriostatic effect for 60 days. All HPP lots stored at 1 degrees C led to counts <100CFU/g at day 60. Similar results were observed when combining both technologies. After a cold chain break no growth of L. monocytogenes was observed in pressurized ham packed with antimicrobial films, showing the efficiency of combining both technologies.

Use of antimicrobial biodegradable packaging to control Listeria monocytogenes during storage of cooked ham.

The antimicrobial effect against L. monocytogenes of biodegradable films (alginate, zein and polyvinyl alcohol) containing enterocins was investigated. Survival of the pathogen was studied by means of challenge tests performed at 6 degrees C during 8 and 29 days, for air-packed and vacuum-packed sliced cooked ham, respectively. Air packaging was tested with two concentrations of enterocins (200 and 2000 AU/cm2). Control air-packed cooked ham showed an increase of L. monocytogenes from 10(4) to 10(7) CFU/g after 8 days. By contrast, packaging with antimicrobial films effectively slowed down the pathogen's growth, leading to final counts lower than in control lots. Air-packaging with alginate films containing 2000 AU/cm2 of enterocins effectively controlled L. monocytogenes for 8 days. An increase of only 1 log unit was observed in zein and polyvinyl alcohol lots at the same enterocin concentration. Vacuum packaging with films containing enterocins (2000 AU/cm2) also delayed the growth of the pathogen. No increase from inoculated levels was observed during 15 days in antimicrobial alginate films. After 29 days of storage, the lowest counts were obtained in samples packed with zein and alginate films containing enterocins, as well as with zein control films. The most effective treatment for controlling L. monocytogenes during 6 degrees C storage was vacuum-packaging of sliced cooked ham with alginate films containing 2000 AU/cm2 of enterocins. From the results obtained it can concluded that antimicrobial packaging can improve the safety of sliced cooked ham by delaying and reducing the growth of L. monocytogenes.

Assessment of high hydrostatic pressure and starter culture on the quality properties of low-acid fermented sausages.

The addition of starter culture and high pressure processing after ripening improved the microbial quality of low-acid fermented sausages (fuet and chorizo). The use of Lactobacillus sakei CTC6626 and Staphylococcus xylosus CTC6013 as starter culture significantly reduced Enterobacteriaceae and Enterococcus levels in the finished sausages. Moreover, the addition of starter culture produced sausages of similar quality to traditional low-acid fermented sausages. Slightly lower pH values and higher cohesiveness were obtained for both fuet and chorizo with starter culture. Sensory analysis showed no differences between lots of chorizo whereas starter fuet was more acid and gummy. High pressure induced an additional reduction of Enterobacteriaceae in non-starter sausages. An increase of textural properties was observed after pressurization. No other differences were observed between non-treated and pressurized sausages.

Starter cultures and high-pressure processing to improve the hygiene and safety of slightly fermented sausages.

The effectiveness of selected starter cultures and high hydrostatic pressure after ripening was evaluated to improve the safety and quality of slightly fermented sausages. Inhibition of common foodborne pathogens, spoilage bacteria, and biogenic amine content was studied. Random amplification of polymorphic DNA and plasmid profiles were used to monitor the competitiveness of the starter cultures during fermentation and ripening. Lactobacillus sakei CTC6626 and Staphylococcus xylosus CTC6013 dominated L. sakei CTC6469 and S. xylosus CTC6169 independently of the product assayed. Starter cultures were able to control the growth of Listeria monocytogenes, Enterobacteriaceae, Enterococcus, and the biogenic amine content. A pH decrease below 5.3 at the seventh day of fermentation was crucial. Salmonella spp. counts decreased significantly during ripening independently of the use of starter culture and product. High hydrostatic pressure treatment was necessary to ensure absence of Salmonella spp. in final products.