• Characterization of functional properties of proteins from Ganxet beans (Phaseolus vulgaris L. var. Ganxet) isolated using an ultrasound-assisted methodology

      Lafarga, Tomas; Álvarez García, Carlos; Bobo, Gloria; Aguilo-Aguayo, Ingrid; Generalitat de Catalunya; Juan de la Cierva contract award; Postdoctoral Senior Grant Ramon y Cajal; FJCI-2016-29541; RYC-2016-19949 (Elsevier, 2018-08-17)
      This study investigated different methods of extraction of protein from Ganxet beans (Phaseolus vulgaris L. var. Ganxet) and evaluated the functional properties of these valuable proteins. Overall, ultrasound processing (40 kHz, 250 W) resulted in higher yields and increased percentages of material solubilized and proteins recovered. The highest percentage of recovered protein was obtained after extraction using 0.4 M NaOH followed by ultrasound processing for 60 min and was calculated as 78.73 ± 4.88% (p < 0.05). Extraction using 0.4 M NaOH followed by sonication for 60 min resulted in the highest yield and percentage of solubilized material calculated as 37.98 ± 0.02 and 54.58 ± 0.19%, respectively (p < 0.05). The water- and oil-holding capacities of the Ganxet protein concentrate were calculated as 2.33 ± 0.12 and 2.69 ± 0.32 g of water or oil per g of protein concentrate, respectively. The highest emulsifying capacity was observed at pH 8.0 and was calculated as 69.4 ± 0.8%.
    • Mechanical and Biochemical Methods for Rigor Measurement: Relationship with Eating Quality

      Álvarez García, Carlos; Morán, Lara; Keenan, Derek F.; Mullen, Anne Maria; Delgado-Pando, Gonzalo; Basque Government; IT944-16 (Hindawi, 2019-06-13)
      Meat quality parameters are affected by a complex series of interacting chemical, biochemical, physical, and physiological components that determine not only the suitability for consumption and the conditions for further processing and storage but also consumer acceptability. Deep understanding and careful manipulation of these intrinsic and extrinsic factors have to be taken in account to ensure high quality of meat, with better technological properties and increased safety for consumers. Among meat quality characteristics, meat tenderness has been perceived as the most important factor governing consumer acceptability. Therefore, being able to early predict meat texture and other related parameters in order to guarantee consistent eating quality to the final consumer is one of the most sought-after goals in the meat industry. Accurate measurements of both the biochemical and mechanical characteristics that underpin muscle and its transformation into meat are key factors to an improved understanding of meat quality, but also this early-stage measurements may be useful to develop methods to predict final meat texture. It is the goal of this review to present the available research literature on the historical and contemporary analyses that could be applied in early postmortem stages (pre-rigor and rigor) to determine the biochemical and physical characteristics of the meat that can potentially impact the eating quality.
    • Novel “gel demineralizing” method for protein recovery from fat rendering waste stream based on its gelling properties

      Álvarez García, Carlos; Drummond, Liana; Mullen, Anne Maria (Elsevier, 2018-11)
      Fat rendering is a common process in the meat industry, whereby fatty or oily materials are melted away or cooked from the solid portion of the animal tissue. Once the fat, and more solid protein in the form of greaves, has been removed a co-product called glue water or stick water is produced which in generally considered a waste product. This study was established to investigate ways to revalorise this product and reduce the economic and environmental impact of this waste material. Proximate characterisation shows it contains 1.1–1.3% w/w of protein along with similar concentration of ashes (1.3% w/w). While low in protein this is a key pollutant if the product is disposed of, and could also represent an interesting protein source for downstream applications. In order to recover these proteins the salt has to be removed. Therefore, after the techno-functional properties of the raw material and of the recovered proteins were evaluated, especially those related to gelling formation, a new demineralizing method based on the excellent gelling properties of these proteins was developed and results compared with those obtained from three different ultrafiltration membranes (10, 3 and 1 kDa MWCO). Protein recovery was greater for the new method (79–90%) (50–77%); however, the amount of salt removed was higher when ultrafiltration was employed (90% compared to 81%).
    • Opportunities and perspectives for utilisation of co-products in the meat industry

      Lynch, Sarah A.; Mullen, Anne Maria; O'Neill, Eileen; Drummond, Liana; Álvarez García, Carlos; Department of Agriculture, Food and the Marine; 11/F/043 (Elsevier, 2018-06-19)
      Meat co-products are the non-meat components arising from meat processing/fabrication and are generated in large quantities on a daily basis. Co-products are considered as low added-value products, and in general it is difficult for industries to divert efforts into increasing their value. While many of these products can be edible those not used for human consumption or pet food is usually processed to be used as animal feed, fertilizer or fuel. However, to a large extent meat co-products are an excellent source of high nutritive value protein, minerals and vitamins and hence may be better diverted to contribute to alleviate the increasing global demand for protein. In this review the current uses, legislation and potential techniques for meat co-products processing are reviewed with the aim of showing a route to improve meat industry sustainability, profitability and better usage of available resources.
    • Optimised protein recovery from mackerel whole fish by using sequential acid/alkaline isoelectric solubilization precipitation (ISP) extraction assisted by ultrasound

      Álvarez García, Carlos; Lélu, Pauline; Lynch, Sarah A.; Tiwari, Brijesh K; National Development Plan 2007–2013; MFFRI/07/01 (Elsevier, 2017-10-04)
      The growing fishery industry needs to find new green-processes in order to provide a solution to the huge amount of wastes and by-products that such industrial activity produces. Currently, around a 40% of the total weight of the mackerel is considered a by-product, because just the fillets are used in the food market. ISP method has been revealed as a useful tool for protein recovering, however the yield of this process is traditionally lower than enzymatic methods. In present work, the use of sequential acid/alkaline extraction and alkaline extraction assisted by ultrasound, have been implemented in order to increase the yield of the process. It has been demonstrated that (i) sequential extraction is able to recover practically 100% of total protein, and (ii) applying ultrasound to alkaline extraction is possible to recover more than 95% of total protein from mackerel by-products. Extracted proteins were characterized according to their size, and the amino acid profile of final product was determined.
    • Optimization of protein recovery from bovine lung by pH shift process using response surface methodology

      Lynch, Sarah A.; Álvarez García, Carlos; O'Neill, Eileen; Keenan, Derek F.; Mullen, Anne Maria; Department of Agriculture, Food and the Marine, Ireland; Teagasc Walsh Fellowship Programme; 11/F/043 (Wiley, 2017-09)
      BACKGROUND Response surface methodology (RSM) was used in a sequential manner to optimize solubilization and precipitation conditions in the recovery of protein from bovine lung using pH shift. RESULTS Separate D‐optimal designs were employed for protein solubilization and precipitation. Independent variables investigated for protein solubilization were time (10–120 min), temperature (4–20 °C), pH (8.0–11.0) and solvent/sample ratio (2.5–10). Variables for protein precipitation were time (0–60 min) and pH (4.25–6.00). Soluble protein yields ranged from 323 to 649 g kg−1 and the quadratic model for protein solubilization revealed a coefficient of determination R2 of 0.9958. Optimal conditions for maximum protein solubility were extraction time 140 min, temperature 19 °C, pH 10.8 and solvent/sample ratio 13.02. Protein precipitation yields varied from 407 to 667 g kg−1, giving a coefficient of determination R2 of 0.9335. Optimal conditions for maximum protein precipitation were pH 5.03 and 60 min. Based on the RSM model, solubilization conditions were manipulated to maximize protein solubilization under reduced water and alkaline usage. These conditions were also validated. CONCLUSION Models for solubilization and precipitation using bovine and porcine lung were validated; predicted and actual yields were in good agreement, showing cross‐species applicability of the results. © 2017 Society of Chemical Industry