A Review of Gelatin Source Authentication Methods

INTRODUCTION

As at 2013, the global Halal market size was about 580 to 660 billion US Dollars and has great potential to increase in the future year (Jahangir et al. 2016). Apart from increasing Muslim population and Halal awareness, Halal market is driven by development of Halal ingredients authentication methods that strengthening consumers’ confident (Malik et al. 2016). Gelatin is among the most studied Halal ingredient because of its vast usage in pharmaceutical and food products. Gelatin is a hydrocolloid with unique properties and can function as gelling, thickener, foaming agent, plasticizer, texture and binding agent (Sahilah et al. 2012).

The sources of most commercial. Gelatin are from mammalian (bovine and mostly porcine). Bone and hide (Shabani et al. 2015). Consumers’ concern about gelatin is due to cultural and religious beliefs. For examples, Muslims and Jews reject porcine based food derivatives, Chinese traditional medicine use only gelatin from donkey skin for treatment of some disease (Nemati et al. 2004) and vegetarians avoid animal based products. Increase in Halal awareness among Muslims has called for great need of food-source authentications. Gelatin and gelatin based products are currently classified as doubtful because haram (porcine) gelatin is the most abundant. Traceability of gelatin has been a great task in Halal field. Other reasons for gelatin source authentication include: (i) protection of consumer from food frauds due to false labeling and avoid unfair market competition (Kesmen et al. 2009) and (ii) health issues. The use of bovine carrying prion proteins has been linked to bovine spongiform encephalopathy (mad cow disease) causing immune response that led to fatal neurodegenerative disease (spongy degeneration of the brain and spinal cord) in cattle (Widyaninggar et al. 2012). Also, bovine and porcine gelatins is risky to gelatin-allergic patients (Raraswati et al. 2013).

Gelatin contains protein

peptides or nucleic acids (Malik et al. 2016). Proteins, peptide derivatives and nucleic acids are favorable means for tissue identification in samples even after it has undergone heating, for instance, in processed food (Buckley et al. 2009). However, large similarities between structures of gelatin from different sources make their differentiation difficult (Nemati et al. 2004). Many gelatin source authentication methods have been developed including: spectroscopic method (Hashim et al. 2010; Hermanto & Fatimah 2013), immunochemical method (Tukiran et al. 2015, 2016a), nucleic acid based method (Cai et al. 2012; Demirhan et al. 2012; Malik et al. 2016; Mutalib et al. 2015; Shabani et al. 2015; Sudjadi et al. 2015), mass spectrometric method HPLC/MS (Yilmaz et al. 2013; G.-F. Zhang et al. 2008; G. Zhang et al. 2009), chromatographic-chemometric method (Azilawati et al. 2015), electrophoretic analysis (Azira et al. 2014) and chemisorption (Hidaka & Liu 2003).

We have reviewed gelatin source authentication methods and identified their achievements and challenges. Current gelatin source authentication methods are time consuming and expensive, thus required development of cheap and quick analytical methods. Likewise, gelatin transformation during processing can potentially hinder the efficiency of the currently developed gelatin authentication methods. This work will serve as a quick reference guide for future researchers.

AUTHENTICATION OF GELATIN SOURCES

As earlier stated, several methods have been developed to investigate sources of gelatin in commercial gelatin or gelatin-containing products. Authentication of gelatin sources in several products have been investigated (Table 1). Researchers have adopted several approaches to develop specie-specific gelatin authentication methods. The approaches include use of the amino acid profile, the presence of specific peptide and DNA markers and the spectral fingerprint of gelatins or its peptides.