Pornsawan Chamnanvatchakit ¹, Thummanoon Prodpran ¹, Soottawat Benjakul ², Surasit Prasarpran ¹

Affiliations
1 Department of Material Product Technology, Faculty of Agro–Industry, Prince of Songkla University, 15 Kanchanawanish Road, Hat Yai, Songkhla – 90112, TH
2 Department of Food Technology, Faculty of Agro–Industry, Prince of Songkla University, 15 Kanchanawanish Road, Hat Yai, Songkhla – 90112, TH

Abstract

Epoxidized Natural Rubber (ENR) was incorporated into bovine gelatin film for enhancing flexibility, water–vapor barrier and water resistance of gelatin film. The impact of gelatin/ENR (G/ENR) ratios (10/0, 8/2, 6/4, 5/5 and 0/10) and ENR types (i.e. ENR–10, ENR–25 and ENR–50 containing epoxy content of 12, 28 and 57 %mol, respectively) on properties of films from bovine gelatin was investigated. As epoxy content and level of ENR increased, the films had decreased tensile strength (TS) and transparency but increased Elongation At Break (EAB) and yellowness (b*–value) (p<0.05). Water–Vapor Permeability (WVP) of gelatin–based films decreased with ENR addition (p<0.05). Incorporation of ENR–25 at the G/ENR ratio of 6/4 rendered the blend film with the increases in EAB (or flexibility) and water–vapor barrier property by approximately 1.8 and 1.3 times, respectively, compared to those of the gelatin film. The improved properties of G/ENR blend films were most likely due to the compatibility between gelatin and ENR associated with their chemical interactions, as evidenced by SEM and FTIR results.

Keywords

Biodegradable Blend Film, Epoxidized Natural Rubber (ENR), Gelatin

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Aneesa Addeen ¹, Soottawat Benjakul ¹, Sajid Maqsood ²

Affiliations
1 Department of Food Technology, Faculty of Agro-Industry, Prince of Songkla University, Hat Yai, Songkhla - 90112, TH
2 Department of Food Science, Faculty of Food and Agriculture, UAE University, Al-Ain, AE

Abstract

Background/Objectives: Loss in quality of chicken meat caused by lipid oxidation mediated by haemoglobin can lead to the rejection. The study aimed to study lipid oxidation and colour of washed chicken as affected by different haemoglobins. Methods/Statistical Analysis: Different forms of haemoglobin from chicken blood including Oxyhaemoglobin (OxyHb) and Methaemoglobin (MetHb) were prepared and added into washed chicken mince to obtain the final concentration of 8 μmole Hb/kg washed mince. Lipid oxidation products, volatile compounds and color in chicken mince samples were monitored during 8 days of the refrigerated storage. Findings: Washed chicken mince added with oxyHb and metHb contained the higher Peroxide Value (PV) and Thiobarbituric Acid-Reactive Substances (TBARS), compared with the control (P<0.05). Oxy-form was more pro-oxidative than met-form as evidenced by the higher PV and TBARS (P<0.05). Volatile lipid oxidation compounds, especially hexanal, were formed at higher rate in the sample added with oxyHb, compared with the control and that added with MetHb. At day 0 of storage, the sample added with oxyHb showed the higher a*-value but lower L* and b* value when compared with the control sample. The decrease in a* value was more pronounced in the sample containing oxyHb at day 8 of refrigerated storage. Thus, lipid oxidation and colour of chicken mince were more likely governed by the form of haemoglobin. Applications/Improvements: Bleeding should be carried out effectively during slaughtering process to prevent the lipid oxidation and discoloration of chicken meat.

Keywords

Chicken Mince, Haemoglobin, Lipid Oxidation

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Rossawan Intarasirisawat ¹, Soottawat Benjakul ¹, Wonnop Visessanguan ²

Affiliations
1 Department of Food Technology, Faculty of Agro-Industry, Prince of Songkla University, Hat Yai, Songkhla – 90112, TH
2 National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, 113 Phaholyothin Rd., Klong 1, Klong Luang, Pathumthani – 12120, TH

Abstract

Background/Objectives: Skipjack Roe Protein Hydrolysate (SRPH) can serve as the natural emulsifier. Nevertheless, homogenising conditions have also shown to determine the stability of emulsion. Thus, the aim of this study was to elucidate the impact of different homogenisation pressures on stability of emulsion containing SRPH. Methods/Statistical Analysis: Emulsions containing SRPH or sodium caseinate were prepared using varying homogenisation pressures (13.8, 20.7 and 27.6 MPa). During the 14 days of extended storage, emulsion samples were tested for particle size, flocculation factor, coalescence index, ζ-potential, creaming index, interfacial protein, confocal laser scanning microscopy and SDSPAGE of interfacial and unabsorbed proteins respectively. Findings: Higher homogenisation pressure resulted in the higher decrease in particle sizes as evidenced by the decreased volume frequency distribution (d43) (P < 0.05). The protein concentration at interface was increased with increasing homogenisation pressures (P < 0.05). Dominant interfacial proteins of SRPH stabilised emulsions had the molecular weight in the range of 7.0-16.4 kDa. During the extended storage, particle size, creaming index, flocculation factor (Ff) and coalescence index (Ci) of SRPH stabilised emulsions sharply increased, especially in emulsions prepared at 20.7 and 27.6 MPa (P < 0.05). Nevertheless, emulsions containing SRPH showed the lower stability, compared with those stabilised by sodium caseinate (P < 0.05). Applications/Improvements: The stability of emulsion stabilised by SRPH could be improved by homogenisation at an appropriate pressure (13.8 MPa).

Keywords

Skipjack tuna, Roe, Emulsion, ζ-potential, Particle size

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