Begonya Marcos

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 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.

Monitoring the effects of high pressure processing and temperature on selected beef quality attributes.

The combined effects of high pressure processing (HPP) and temperature on meat quality attributes were assessed in bovine M. pectoralis profundus, with particular focus on lipid oxidation and fatty acid composition. Beef samples were pressurised at 200, 300 and 400 MPa at two different temperatures 20°C and 40°C. Both pressure and temperature regimes had significant effects on colour, cook loss and lipid oxidation. Pressurisation at 200 MPa had a lower impact on colour parameters than higher pressurisation levels. Cook loss also increased when higher levels of pressure were applied. Across all pressure conditions, lower cook loss was observed at 40°C compared to 20°C. An increase in TBARS values was observed at the higher pressure levels (300, 400 MPa). While some alterations of individual fatty acids were observed, high pressure had no effect on polyunsaturated/saturated fatty acid (PUFA/SFA) or omega 6/omega 3 (n6/n3) ratio. The temperature at which HPP was applied had a significant effect on the sum of saturated (SFA), monounsaturated (MONO) and polyunsaturated (PUFA) fatty acids. HPP at 40°C showed higher SFA and PUFA and lower MONO compared to HPP at 20°C. These results show that high pressure at low or moderate temperatures improves the microbiological quality of the meat with minimal affects on meat quality.

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.

Aminogenesis control in fermented sausages manufactured with pressurized meat batter and starter culture

The application of high hydrostatic pressure (200MPa) to meat batter just before sausage fermentation and the inoculation of starter culture were studied to improve the safety and quality of traditional Spanish fermented sausages (fuet and chorizo). Higher amounts of biogenic amines were formed in chorizo than in fuet. Without interfering with the ripening performance in terms of acidification, drying and proteolysis, hydrostatic pressure prevented enterobacteria growth but did not affect Gram-positive bacteria significantly. Subsequently, a strong inhibition of diamine (putrescine and cadaverine) accumulation was observed, but that of tyramine was not affected. The inoculated decarboxylase-negative strains, selected from indigenous bacteria of traditional sausages, were resistant to the HHP treatment, being able to lead the fermentation process, prevent enterococci development and significantly reduce enterobacteria counts. In sausages manufactured with either non-pressurized or pressurized meat batter, starter culture was the most protective measure against the accumulation of tyramine and both diamines.

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.

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 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.

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.