Facilitating shrimp ( Pandalus borealis ) peeling by power ultrasound and proteolytic enzyme (original) (raw)
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Enzyme-assisted peeling of cold water shrimps ( Pandalus borealis )
Innovative Food Science & Emerging Technologies, 2018
An enzymatic method to facilitate the peeling of cold water shrimps (Pandalus borealis) was developed. The protease solutions were used to mature the shrimps to promote shell-loosening prior to peeling. The efficiency of peeling enzyme-treated shrimps was evaluated by a new quantitative measurement based on the tensile force, presented as a peelability profile. It was found that enzymatic maturation efficiently improved the peelability of shrimps. The factors affecting the peelability of the enzyme-matured shrimps were the type of enzyme, enzyme concentration and maturation duration, while changes in pH had no impact. Maturation of shrimps in solutions of the endoproteases Endocut-01L (180 NU/g) and Endocut-03L (60 U/g) and the exoprotease Exocut-A0 (100 U/g) resulted in better peelability compared to shrimps matured in endoprotease Tail21 (65 U/mL) and 2% NaCl. A combination of 0.25% Endocut-03L and 0.25% Exocut-A0 for 20 h resulted in the best peeling of shrimps (100% completely peeled shrimps, 3 mJ/g work and 89% meat yield). Reuse of the enzyme solution was possible due to a 95% retention rate of proteolytic activity after two 20-h cycles of maturation. The studied enzymatic maturation offered a better shrimp product with respect to texture and color in comparison with an industrial brine-matured reference, i.e.,~22% higher redness and~31% higher hardness. Industrial relevance: Enzymatic maturation is an attempt made as a pre-treatment to facilitate the removal of the shell from meat of shrimp. This approach would benefit the shrimp processing industry by 1) enhancing peeling efficiency that includes least efforts to remove the shell, high rate of completely peeled shrimps and high meat yield; 2) shortening the duration of maturation but still sufficiently loosening the shell for machine peeling; 3) performing as a chemical-free peeling aid, which may increase the preference of consumers over chemical compounds; and 4) being environmentally friendly since disposal of enzyme waste is harmless to the environment. 1. Introduction Cold water shrimp, Pandalus borealis, is one of the most commercially important species of wild shrimps in the world (Myrset, Barletta, Di Felice, Egaas, & Dooper, 2013). The shrimp is diversely named as Northern shrimp (FAO), pink shrimp or deep-water prawn (UK, Canada and USA) and deep-sea prawn (Canada) (Holthuis, 1980). P. borealis is caught mainly in the North Atlantic, especially around Greenland, the Gulf of St. Lawrence, the Bay of Fundy, the Gulf of Maine and North Pacific (Holthuis, 1980). The global catch of P. borealis constantly decreased from around 446,909 tons in 2004 to around 260,488 tons in 2015 according to (FAO, 2017). Research in shrimp processing for improvements in efficiency, yield and quality is, therefore, important for economic sustainability. Shell-loosening is an important step in processing of peeled shrimps. Structurally, the shell is tightly attached to the epidermis by attachment fibers (intracuticular fibers), and the epidermis is securely attached to the muscle by extensive interdigitation (Talbot, Clark Jr, & Lawrence, 1972). Thus, a pre-treatment is needed in order to loosen the muscleshell attachment prior to peeling. Such pre-treatment is called maturation process. The current maturations of shrimps on ice and/or in brine (typically NaCl or NaCl with phosphates) solution for several days are the most common practices to facilitate the separation of the edible meat from the shell in the shrimp industry (Dang et al., 2018). Nevertheless, shrimp is highly perishable, and such long times of maturation may lead to diminish the meat quality e.g., freshness, texture, color, flavor. The intrinsic enzymes in the shrimp and enzymes from microorganisms during post-mortem storage are accountable for enhancing shell removal (Crawford, 1980). Addition of enzymes from external
Emerging and potential technologies for facilitating shrimp peeling: A review
Innovative Food Science & Emerging Technologies, 2018
Ready-to-eat shrimp processing is challenging due to the complex biological design with the shell tightly connected to the meat. Several techniques have been developed to weaken or loosen this connection, thus facilitating the subsequent peeling. The loosening process is typically undertaken by maturing the shrimps on ice or in brine, which requires several days, consequently risking loss in food quality and safety. To overcome those issues, developing novel technologies that not only assist the shell loosening but also retain the meat quality, safety and yield, is of paramount importance. This article reviews some essential characteristics of shrimp, the current methods of maturation, the use of the emerging technologies (high pressure, microwave, ultrasound, and enzyme) to facilitate the peeling of foods and clarify the potential of using them in shrimp shell removal. Industrial relevance During the production of peeled products, the shrimp processing industry has suffered from drawbacks of the traditional ice/brine maturations-a step facilitating the peeling. The drawbacks include yield loss, reduction of organoleptic quality, risk of microorganisms, time consuming issue and discontinuous process due to a long time soaking in maturing tanks. Therefore the need for seeking alternative methods to replace the traditional long maturations has grown, that address the future trends in sustainable processing of ready-to-eat shrimps. Emerging technologies e.g. high pressure, enzyme, ultrasound and microwave can potentially become the alternatives since they have strong peeling effects on lobsters, crabs, bivalve mollusks, eggshells, human skin, fruits and vegetables. Also these technologies offer benefits such as short process time, retained nutritional and sensorial characteristics, energy and water efficiency which all promise higher profits for the shrimp industry.
Foods, 2020
Canned pāua, Haliotis iris, is a premium New Zealand product that is exported to Asia. The objective of this research was to investigate the effects of ultrasound treatments on pāua texture, microstructure and in vitro protein digestibility. Whole pāua meat was ultrasound-treated (20 kHz, 464 ± 9 W) for 5 min in water (with or without subsequent soaking in water at 4 °C for 24 h) or ultrasound-treated in 1% actinidin enzyme solution. Post-treatment cooking of canned pāua was done in a water retort at 116 °C for 30 min. All ultrasound-treated cooked pāua yielded lower slice shear force values (SSFV) than untreated canned and cooked samples. The lowest SSFV was attained when ultrasound treatment in water was followed by soaking at 4 °C for 24 h. The increased tenderness of ultrasound-treated pāua could be linked to disintegration of myofibers and formation of gaps between myofibers, as observed through histological analysis and transmission electron microscopy. Collagenous fragmentati...
Innovative Food Science & Emerging Technologies, 2019
This study aimed at understanding the effects of high pressure (HP) and ohmic heating (OH) on the peelability, the underlying mechanisms of HP-and OH-induced shell tightening, the thermal and structural properties of shrimp parts. HP improved the peelability of shrimp at low pressure level (<350 MPa) and short holding time (≤3 min) and the optimum condition for peeling was at 100 MPa for 3 min at 5°C. However, a higher pressure level (>350 MPa) led to a decrease in the peelability. High pressure at 600 MPa stabilized cuticular and epidermal collagen and formed new collagen-like structures by new linkages, which strengthened the muscle-shell connection and reduced the peelability. Shrimp meat induced from HP at 100 MPa and 600 MPa had minorly denatured myofibrillar proteins. OH as a blanching method did not significantly improve the peelability of shrimp at most of the studied conditions. Some extreme conditions (e.g. at 50°C) caused a markedly low peelability due to occurrence of collagen gelatinization. The gel formation from collagen-gelatin transformation under heating added strength to adherence of shell to epidermis and muscle, as a consequence, a difficult peeling was experienced. OH also denatured proteins in shrimp meat and caused loss of astaxanthin. Industrial relevance: The industrial processing of ready-to-eat shrimp involves the on-ice or in-brine maturation process which loosens the shrimp's shell from its meat, and therefore enable the mechanical peeling. However, the traditional maturation is time consuming (up to 4-5 days), inevitably leads to reduced quality of shrimp meat. This study shows the possibility of the application of HP at mild pressure levels to promote the shell loosening at short HP processing time (≤3 min). However, at more severe HP conditions could lead to the shell tightening which was caused by HP-induced stabilization of collagen in shell and epidermis. The study also shows that ohmic heating (<5 min) might not be a significant blanching method to support the maturation since OH had minor positive effect on shell loosening at 3 some OH conditions (e.g. 2 or 10% NaCl, 92V, and 30 or 35°C), but had a counter effect at most OH conditions especially at high temperature.
Maintaining functional properties of shell eggs by ultrasound treatment
Journal of the Science of Food and Agriculture, 2014
Ultrasonic treatment is an emerging technique that could be an alternative to existing thermal processing techniques in foods. Ultrasonic treatments may also be used to extend the shelf life of egg during storage period in ambient temperature. The effectiveness of ultrasound treatment with different power levels (200 W, 300 W, 450 W) and treatment times (2 min and 5 min) was evaluated for enhancing the functional properties of eggs during storage at 24 ° C for 6 weeks. Ultrasound treatment power and treatment time had significant effects on Haugh unit, yolk index, albumen pH, dry matter, relative whipping capacity, and albumen viscosity resulting in extended shelf life. Attributes such as yolk index, Haugh unit, pH, whipping capacity, dry matter for 300 W and 450 W treatments were better than control and 200 W treatments. Longer treatment time and power showed a significant influence on functional properties. Power levels of 300 W and 450 W of ultrasound treatments had improved internal quality of fresh eggs during storage, but negative effect on shell strength. The study showed that ultrasound treatment could be an alternative and effective technique for maintaining the internal qualities of fresh eggs during long-term storage while Fourier transform near infrared spectroscopy could be used as a new tool for the assessment of freshness. © 2014 Society of Chemical Industry.
Applied Sciences
Ultrasonic pulses are considered green technology for the improvement of the functional properties of proteins. In this study, four high-intensity ultrasound pulse treatments (ultrasound-pulsed gelatin (UPG)-42, UPG-52, UPG-71, UPG-84, and non-pulsed control gelatin (CG)) were applied to tilapia (Oreochromis niloticus) skin gelatin in order to study their effect on its physicochemical and antioxidant properties; a non-treated gelatin was used as a control. UPGs showed a significant increase in soluble protein and surface hydrophobicity compared to the control gelatin, and no significant difference was found in the electrophoretic profiles. The effects on the secondary structure were studied by circular dichroism and infrared spectra, and these showed that the random coil conformation was the main component in all treatments and the ultrasonic treatments only affected the α-helix and β-sheet proportion. Finally, the ABTS ((2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid)) and ...
A quantitative method to measure and evaluate the peelability of shrimps (Pandalus borealis)
LWT, 2018
A novel, standardized method has been developed in order to provide a quantitative description of shrimp peelability. The peeling process was based on the measure of the strength of the shellmuscle attachment of the shrimp using a texture analyzer, and calculated into the peeling work. The self-consistent method, insensitive of the shrimp size, was proven valid for assessment of ice maturation of shrimps. The quantitative peeling efficiency (peeling work) and performance (degree of shell removal) showed that the decrease in peeling work correlated with the amount of satisfactory peeled shrimps, indicating an effective weakening of the shell-muscle attachment. The developed method provides the industry with a quantitative analysis for measurement of peeling efficiency and peeling performance of shrimps. It may be used for comparing different maturation conditions in relation to optimization of shrimps peeling.
2016
We evaluated the effects of ultrasonic cleaning on mollusk shells using scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis. The objective was to investigate the effects of this cleaning approach on the organic layer of the shells (the periostracum) and to assess the efficacy of a thin coating of consolidant to protect shells from vibrations. We found that ultrasonic cleaning caused abrasion of the shell surface. Treated specimens showed a flaky exterior, while non-treated specimens showed a more homogenous surface. Pre-treatment with TEOS-based consolidant did not prevent loss of the superficial layer and precipitated solid crystals on the surface. Our findings indicate that ultrasonic cleaning should be used with caution for fragile specimens because it can substantially alter the surface of
Extraction efficiency and physiochemical properties of acid and pepsin soluble collagens from the skin of golden carp (Probarbus jullieni) as influenced by ultrasonication were studied. The ultrasound treatment (20 kHz) with increasing amplitudes from 20 to 80% increased the yield of acid soluble collagen (ASC) (P < 0.05). When the ultrasound at an amplitude of 80% was employed in combination with pepsin (0.1. 0.5 and 1%), the marked increase in pepsin soluble collagen (PSC) was obtained when pepsin level increased (P < 0.05). The yield of ASC and PSC increased as ultrasonication time increased (P < 0.05). ASC and PSC with ultrasound aided process, named as UASC and UPSC, had the yields of 81.53 and 94.88%, while ASC and PSC prepared with typical method showed the yields of 51.90 and 79.27%, respectively. All the collagens, with similar amino acid composition, contained α- and β