Vol 2, No 2 (2021) 56–62

Devel­op­ment of Gelatin from Halal and Alter­na­tive Sources: A Review

Farhani Ahmad ¹, Mus­fi­rah Azmi ¹, Nurhamieza Md Huzir ¹ and Norhi­dayu Muhamad Zain ²

¹ School of Ener­gy Engi­neer­ing, Fac­ul­ty of Engi­neer­ing, Uni­ver­si­ti Teknolo­gi Malaysia, 81310 Sku­dai, Johor, Malaysia.
² Acad­e­my of Islam­ic Civ­i­liza­tion, Fac­ul­ty of Social Sci­ence and Human­i­ties, Uni­ver­si­ti Teknolo­gi Malaysia, 81310 Sku­dai, Johor, Malaysia.

Cor­re­spon­dence should be addressed to Norhi­dayu Muhamad Zain; norhidayu_​mz@​utm.​my

Cite this: Nusan­tara Halal J. 2021, Vol. 2 No.2 pp. 56–62 (Review) | Received 10 Sep­tem­ber 2021 | Revised 16 Novem­ber 2021 | Accept­ed 21 Decem­ber 2021 | Pub­lished 29 Decem­ber 2021 | http://​dx​.doi​.org/​1​0​.​1​7​9​7​7​/​u​m​0​6​0​.​2​0​2​1​v​2​p​0​5​6​-​062

Abstract

Gelatin is a com­mon ingre­di­ent used in var­i­ous indus­tri­al sec­tors includ­ing food and bev­er­age, cos­met­ic, phar­ma­ceu­ti­cal as well as bio­med­ical. Due to inex­pen­sive pro­cess­ing cost and short­er pro­cess­ing time, porcine becomes the main source of gelatin. Thus, the appli­ca­tion of this ingre­di­ent cre­ates sev­er­al prob­lems espe­cial­ly issues relat­ed to its halal sta­tus among Mus­lim com­mu­ni­ty. The present study aims at review­ing the devel­op­ment of gelatin from halal sources and their poten­tial as alter­na­tives to sub­sti­tute the sources of non-halal gelatins. The appli­ca­tions of gelatin in food indus­try and the cur­rent issues on halal gelatin have been dis­cussed in detail. The halal source of gelatin required intense study due to promi­nent demand of it not only in food indus­try but also in phar­ma­ceu­ti­cal indus­try. The devel­op­ment of halal gelatin pro­vides Mus­lim alter­na­tives and choic­es to con­sume gelatin as food and phar­ma­ceu­ti­cal prod­ucts and yet com­ply­ing with Islam­ic obligations.

Key­words: Gelatin, Food Indus­try, Islam­ic, Halal, Alter­na­tive Sources.

Introduction

In the last few decades, food man­u­fac­tur­ing has been pre­pared based on the expan­sion of mod­ern sci­ence and tech­nol­o­gy. There are quite a lot of ingre­di­ent sources which have been used in the pro­duc­tion of food prod­ucts includ­ing gelatin. Gelatin is a pro­tein derived from col­la­gen, acquired by heat­ing col­la­gen exceed­ing its denat­u­ra­tion tem­per­a­ture that will lead to a struc­tur­al col­lapse. Gelatin basi­cal­ly is made up of 19 amino acids vast­ly con­tent of hydrox­ypro­line, pro­line and glycine, thus it has low­er mol­e­c­u­lar weights than col­la­gen [1].

The func­tions of gelatin in food indus­try include improv­ing the tex­ture of the food, increas­ing preser­va­tion of the food in low tem­per­a­ture, refin­ing sta­bil­i­ty, and extend­ing shelf life. In can­dy man­u­fac­tur­ing, gelatin acts as the gelling agent in gel can­dies, adhe­sives agent in chew­ing gum and emul­si­fi­er in fruity cream can­dy. While in the pro­duc­tion of processed meat like head cheese, chick­en rolls and jel­lied meat, gelatin is used to absorb meat juices and give strength to the prod­ucts. Gelatin turns out to be irre­place­able sup­port­ing mate­ri­als in food indus­try for its ulti­mate phys­i­cal prop­er­ties, great puri­ty con­tent and var­i­ous uses [2].

In term of reg­u­la­tion halal gelatin, it does not only focus­ing on the resources being used but also the process that is being implent­ed to pro­duce prod­ucts. The Halal con­cept must be pro­tect­ed through­out the sup­ply chain ‘from farm to fork’. The whole process­es from choos­ing ani­mal sources to pro­duce gelatin, slaugh­ter­ing, extract­ing, man­u­fac­tur­ing, pack­ag­ing and all the way to the con­sumer must be com­plied to Shari­ah law.

There are abun­dance sources of non-Halal gelatin, and the sources of the ingre­di­ent are not stat­ed at the food pack­ag­ing, mak­ing con­fu­sion to the Mus­lim con­sumer. Despite of this sit­u­a­tion, there are oth­er options and many alter­na­tives to sub­sti­tute this aux­il­iary food ele­ment. There­fore, the major pur­pose of this paper is to report on cur­rent devel­op­ment of Halal sources gelatin and to list out the alter­na­tives to replace the non-Halal gelatin.

Functional Properties of Gelatin

The prop­er­ties of gelatin based on the source and type of col­la­gen used dur­ing pro­duc­tion process. The func­tion­al prop­er­ties of gelatin can be divid­ed into two groups which are gelling and sur­face prop­er­ties. The gelling prop­er­ties include gel strength, vis­cos­i­ty, and gelling time, set­ting, and melt­ing tem­per­a­tures, thick­en­ing, and tex­tur­iz­ing and water reten­tion prop­er­ties. The gelatin’s sur­face prop­er­ties pro­vide infor­ma­tion regard­ing film for­ma­tion and adhesion/​cohesion, emul­sion for­ma­tion and sta­bi­liza­tion, pro­tec­tive col­loid func­tion, foam for­ma­tion and sta­bi­liza­tion  [3].

Gelatin has many spe­cial prop­er­ties which are not eas­i­ly imi­tat­ed by hydro­col­loids such as ‘‘melt-in-the-mouth’’ prop­er­ties that melt­ing slight­ly below body tem­per­a­ture (<35˚C). It gives the poly­mer the spe­cial ‘‘melt-in-mouth’’ per­cep­tion lead­ing to inten­sive fla­vor and aro­ma release [1]. Based on the pre­vi­ous stud­ies, sci­en­tists have not been able to find a gelling pro­tein or poly­sac­cha­ride, which uni­ver­sal­ly able to replace gelatin as a gelling agent (Karim and Rajeev, 2008). Unlike most pro­tein and oth­er poly­sac­cha­ride gels, gelatin gels are ther­more­versible. They can reversibly turn into liq­uid from gelling from when heat­ed at cer­tain tem­per­a­ture. Some plant hydro­col­loids such as car­rageenan and agar can per­form ther­mal­ly reversible gels too, how­ev­er the melt­ing points are slight­ly high­er than that gelatin gels [2].

Anoth­er impor­tant fea­ture of gelatin is the sur­face activ­i­ty. Gelatin does not have high sur­face activ­i­ty when com­pared to gum Ara­bic. The emul­si­fy­ing or sta­bi­liz­ing prop­er­ties are low­er than that of gum Ara­bic, yet this char­ac­ter­is­tic of gelatin is cru­cial espe­cial­ly when com­bine with the gel form­ing abil­i­ties of gelatin [4]. Gelatin can be con­sid­ered as one of the most ver­sa­tile hydro­col­loids in food indus­try. Due to its vast mul­ti-func­tion­al prop­er­ties cov­er­ing from gelling, thick­en­ing, water-bind­ing, emul­si­fy­ing, foam­ing, film-foam­ing agents, gelatin known as irre­place­able hydro­col­loid since no oth­er sin­gle hydro­col­loid gives the same com­bi­na­tion of func­tion­al­i­ties [4].

Gelatin is avail­able in dif­fer­ent gel strengths and par­ti­cle sizes based on spe­cif­ic appli­ca­tions. In con­trast, plant hydro­col­loids do not have the gel strengths. Mod­i­fi­ca­tion of jel­ly strength must be blend­ing with oth­er ingre­di­ents such as sug­ars and salts. Oth­er than that, the gel of gelatin is con­ve­nient to be used with­in the nor­mal pH range suit­able for most foods and it does not require the addi­tion of salts or sug­ars. Gelling hydro­col­loids fre­quent­ly require the addi­tion of salts, sug­ars or food acids to make a gel [5].

Sources of gelatin

The sources of gelatin can be agri­cul­tur­al like hydro­col­loid or non-agri­cul­tur­al source such as sources from cat­tle bones, hides, pig skins, and fish [6]. These sources can be Halal or non-Halal gelatin.

Porcine and bovines

Gelatin obtained from porcine are known as Type A Gelatin and wide­ly used in food indus­try. Grad­u­ate Med­ical Edu­ca­tion, GME (2008) reports the annu­al world pro­duc­tion of gelatin is near­ly 326,000 tons per year [7] fol­lowed by bovine hides (29.4%), bones (23.1%) and oth­er sources (1.5%) [7]. This type of gelatin is processed in a short­er peri­od by mix­ing with acid and even­tu­al­ly pro­duc­ing good qual­i­ty and great amount of prod­uct (Type A gelatin). Anoth­er types of gelatin is Type B Gelatin obtained from bovines’ bones and skins like cows and buf­faloes which requires lengthy treat­ment with alka­li or lime water [8]. The pur­pose of alka­li or acid pre-treat­ment is to bro­ken the struc­ture of col­la­gen, sol­u­bi­lize the non-col­la­gen pro­teins and hydrolyze the pep­tide bonds, yet main­tain­ing the con­sis­ten­cy of the col­la­gen fibers [9]. The raw mate­ri­als derived from these mam­mals are lim­it­ed and the price is high­er com­pared to porcine.

Gelatin alternatives

Gelatin replace­ment has been dis­cussed in recent years due to the emerg­ing and prof­itable veg­e­tar­i­an, Halal, and kosher mar­kets. It has recent­ly gained increased inter­est, and sci­en­tists have been stud­ied regard­ing these issues espe­cial­ly with­in Europe due to emer­gence of bovine spongi­form encephalopa­thy (BSE) known as ‘mad cow dis­eases’ in the 1980s and mouth dis­ease (FMD) [5]. Since that, there has been much con­cern about using gelatin derived from infect­ed ani­mal parts. There­fore. A few alter­na­tives to replace the source of gelatin from mam­mals to oth­er poten­tial sources have been proposed.

Hydro­col­loid

Hydro­col­loid is one of the alter­na­tives to replace the mam­malian sources. Hydro­col­loids can be defined as hydrophilic poly­mer most­ly derived from nat­ur­al poly­sac­cha­ride sources that dis­persed in water like sea­weed. The prop­er­ties of hydro­col­loid are sol­u­bil­i­ty [10], vis­cos­i­ty includ­ing thick­en­ing and gelling and water bind­ing but also impor­tant in emul­sion sta­bi­liza­tion, pre­ven­tion of ice recrys­tal­liza­tion and organolep­tic prop­er­ties. Anoth­er appli­ca­tion of hydro­col­loid include adhe­sion, sus­pen­sion, floc­cu­la­tion, foam sta­bi­liza­tion and film formation. 

Unlike gelatin, hydro­col­loid do not have the defined melt set char­ac­ter­is­tics such as gel­lan, algi­nate or car­rageenan-based gels. The poly­sac­cha­ride-based gelatin alter­na­tives gen­er­al­ly have less flex­i­ble mol­e­c­u­lar back­bones, lead­ing to high­er vis­cosi­ties than gelatin [5].

Poul­try

Poul­try sources like chick­en and duck are oth­er alter­na­tives used to replace mam­malian sources for Halal gelatin pro­duc­tion. Poul­try can be used to replace the gelatin if the ani­mal obtained from trust­ed sources and slaugh­tered in Islam­ic way [3,7]. New gelatin sources such as poul­try skin, feet, bone, and eggshell have been used to replace mammalian.

Gelatin pro­duc­tion from waste prod­uct of poul­try espe­cial­ly from the feet of poul­try con­tain high con­cen­tra­tion of col­la­gen com­pared to poul­try skin. Col­la­gen extract­ed from chick­en broil­er feet had high­er hyprox­ypro­line (Hyp) and pro­line (Pro) con­tent and exhib­it­ed high­er ther­mal sta­bil­i­ty. The vast chick­en and duck pro­duc­tion in Malaysia has pro­duce poul­try waste by-prod­ucts (feet), and pro­vide read­i­ly avail­able raw mate­r­i­al source to pro­duce poul­try feet gelatin [7]. In South Korea, a tra­di­tion­al Kore­an gel-type food have been done pre­vi­ous­ly stud­ies on the fea­si­bil­i­ty of using chick­en feet to replace cowhides for jokpyun [7].

Chick­en gelatin has a chem­i­cal com­po­si­tion like bovine gelatin and bet­ter physic­o­chem­i­cal prop­er­ties com­pared with those report­ed for fish gelatins. The gel strength of chick­en gelatin was sig­nif­i­cant­ly high­er than that of bovine gelatin and both formed sta­ble struc­tures on cool­ing. Chick­en gelatin showed high­er gelling tem­per­a­tures com­pared to bovine gelatin [9].

Apart from feet, skin derived from poul­try has a poten­tial as an alter­na­tive sources of Halal gelatin. Norizah [11] report­ed that gel strength from chick­en skin-gelatin has sig­nif­i­cant­ly high­er bloom val­ue (355)compared with those of bovine gelatin (229) Chick­en skin con­tains about 75% type I and 15% type III col­la­gens [7]. Chick­en skin is poten­tial­ly made into ani­mal meal and the oth­er small­er pro­por­tion is used in mak­ing meat emul­sions or used as a source of fat such as for soup preparation.

Fish

Gelatin from marine sources is a bet­ter alter­na­tives to replace bovine gelatin as they have low­er melt­ing point in which it can speed up the dis­so­lu­tion process in the mouth with no resid­ual ‘chewy’ mouth­feel [3]. Fish gelatin is accept­able for Islam and can be used with min­i­mal restric­tions in Judaism and Hin­duism. Unlike mam­malian, marine gelatin sources are not relat­ed with the risk of out­breaks of Bovine Spongi­form Encephalopa­thy. Gelatin can be extract­ed from skins and bones of var­i­ous cold-water (e.g., cod, hake, Alas­ka pol­lock, and salmon) and warm-water (e.g., tuna, cat­fish, tilapia, Nile perch, shark, and megrim) fish. Major byprod­uct of the fish-pro­cess­ing indus­try such as fish skin pro­vides a valu­able source of gelatin [5]. The cold-water fish gelatins basi­cal­ly exhib­it good film for­ma­tion and have high qual­i­ty of emul­si­fy­ing prop­er­ties. Recent­ly, the main appli­ca­tion areas are to pro­duce phar­ma­ceu­ti­cal prod­uct, an implant from oil-based vit­a­mins in by using spray-dry­ing or using micro-encap­su­la­tion tech­niques. In con­trast, the warm-water fish gelatin pro­duced good gelling prop­er­ties and is used in the food and phar­ma­ceu­ti­cal indus­tries [3].

Fish skin con­tains a large amount of col­la­gen. Fish col­la­gens have low­er imi­no acid con­tents com­pared to than mam­malian make it have low­er denat­u­ra­tion tem­per­a­ture (Karim and Rajeev, 2008). It was report­ed that the main dif­fer­ences between fish and mam­malian gelatin is the con­tent of the imi­no acids pro­line and hydrox­ypro­line, which sta­bi­lizes the con­for­ma­tion con­fig­u­ra­tion gelatin in form­ing gelatin gel net­work. The low­er per­cent of pro­line and hydrox­ypro­line result­ing in low gel mod­u­lus, gelling, and melt­ing tem­per­a­ture of fish gelatin. Cold-water fish gelatin like pol­lock and salmon, have low gelling tem­per­a­ture (8˚C) and melt­ing tem­per­a­tures com­pared to mam­malian and warm-water fish gelatins (Karim and Rajeev, 2008).

Insects

Insects are anoth­er source of gelatin that is accept­able for Muslim’s con­sump­tion, but the uti­liza­tion of this type of source is still lim­it­ed. In Sudan there are many edi­ble insects and desert locust insect species is the most famous one in that coun­try beside sorghum and mel­on bugs. Mel­on bug, Aspon­go­pus vid­u­a­tus and sorghum bug, Agonoscelis pubes­cents, also known as Um-bug­ga and Dura andat in Sudan [12] The col­lect­ed bugs were extract­ed and the oil pro­duced from the process was used for cook­ing and some med­i­c­i­nal pur­pos­es [6].

Three dif­fer­ent meth­ods of extrac­tion were used to extract gelatin from A. vid­u­a­tus and A. pubes­cents which were mild acid and dis­tilled water extrac­tion method, dis­tilled water extrac­tion method and extrac­tion with hot water method. Based on the three meth­ods used, the extrac­tion of insect gelatin using hot water gave high­er yield extrac­tion of gelatin up to 3.0% fol­lowed by mild acid extrac­tion 1.5% and dis­tilled water extrac­tion 1.0%, respec­tive­ly [6].

Camel

Camel is one of new source of Halal gelatin alter­na­tive that still being under stud­ies. Camel is an impor­tant ani­mal in Sau­di Ara­bia, and it is expect­ed that the pro­duc­tion of Halal gelatin derived from camel will assist the devel­op­ment of Halal indus­try and Halal busi­ness in the coun­try. The extrac­tion and char­ac­ter­i­za­tions of gelatin derived from camel have been car­ried out in the pre­vi­ous stud­ies [13]. The physic-chem­i­cal, nutri­tion­al, rhe­o­log­i­cal and qual­i­ty prop­er­ties of the camel gelatin is com­pared to oth­er types of gelatins, bovine, and porcine gelatins. In anoth­er study, gelatin has been extract­ed from camel hide and the pro­duced gelatin showed the bloom strength of 152g which is com­pa­ra­ble to oth­er gelatin that are read­i­ly avail­able in the mar­ket like bovine and porcine [13].

Current issues on halal gelatin

Nowa­days Halal issue become a hot top­ic in the mar­ket and since Malaysia is an Islam­ic coun­try, of course Halal con­cept is an impor­tant key point in food indus­try. The abun­dance of non-Halal gelatins which are eas­i­ly avail­able in the mar­ket due to low cost and mass pro­duc­tion by non-Mus­lim com­pa­nies has cre­at­ed a major issue in the Halal indus­try. The main source for the non-Halal gelatin is derived from porcine. Swine resources are becom­ing sus­tain­able due to their eli­gi­bil­i­ty in almost coun­tries in the world. Oth­er than that, there are also lots of unde­clared ingre­di­ents in the food pack­ag­ing. The raw mate­ri­als of the ingre­di­ent are very hard and chal­leng­ing to be test­ed because the prod­ucts are com­ing from all around the world, leav­ing a ques­tion mark about their Halal status.

Anoth­er issue is the con­fu­sion in the use of ‘pork-free’ term. In the mar­ket, the con­cept of Halal is not only restrict­ed to the pork meat or the term ‘pork free’. The term of ‘pork free’ is not enough because it can­not encom­pass the whole con­cept of Halal. Some­times the food does not con­tain any pork meat but still has the ele­ment of pig or we call it as porcine. The pro­duc­er of gelatin espe­cial­ly the non-Mus­lim should have a depth under­stand­ing about the Halal con­cep­tion. They must obey the Islam­ic Law, which com­prise a ban on using any pig-base prod­ucts. A Halal gelatin must be derived from Bovine sources and that sources must be slaugh­tered accord­ing to the Shari­ah Law, marine and oth­er sources which can be con­sid­ered Halal.

Com­mon­ly, when soci­eties talk about Halal, there is a miss­ing ele­ment which is tayy­iban. It is a com­pul­so­ry for halal and tayy­iban con­cept to be applied togeth­er. If the ele­ment of tayy­iban is miss­ing, the food is no longer be con­sid­ered as Halal. Tayy­iban con­cepts con­sist of good, healthy, safe, clean, nutri­tious, and high qual­i­ty of halal prod­ucts. Tayy­iban can be defined by the whole­some­ness of the food in which cov­ers the per­mis­si­ble require­ments of Islam­ic Law. Even if the pro­duc­er claim that their gelatin is pro­duce from Halal bovine and slaugh­tered prop­er­ly accord­ing to syari’ah, but their work­place is dirty and not hav­ing a Good Hygien­ic Prac­tice (GHP) and Good Man­u­fac­tur­ing Prac­tice (GMP), their halal sta­tus can be withdrawn.

Conclusions

Through­out the indus­try, Halal neces­si­ties must be obeyed to at all phas­es of the pro­duc­tion and sup­ply chain, as well as pro­cure­ment of raw mate­ri­als and ingre­di­ents, logis­tics and trans­porta­tion, pack­ag­ing, and label­ing. Mus­lims only allow­ing the use of gelatin derived from Halal ani­mals and they must be slaugh­tered in the name of Allah. Mean­while, gelatin extract­ed from porcine based, and any Haram ani­mals even being slaugh­tered in the name of Allah, is strong­ly for­bid­den. This inter­dic­tion is due to the DNA of porcine that remain unchanged even though it has under­gone a series of chem­i­cal food pro­cess­ing. What has been stat­ed in Al-Quran as Haram is Haram and there is no doubt of it.

Acknowledgments

This study is a part of a research con­duct­ed for Phi­los­o­phy of Sci­ence and Civ­i­liza­tion (UICW 6023) course in Uni­ver­si­ti Teknolo­gi Malaysia and was sup­port­ed by Uni­ver­si­ti Teknolo­gi Malaysia, GUP Tier 2 Grant (Q.J130000.2653.16J05). The authors also would like to thank Min­istry of Edu­ca­tion, Malaysia.

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Copyright

© 2021 by the authors. This is an open access arti­cle dis­trib­uted under the Cre­ative Com­mons Attri­bu­tion License, which per­mits unre­strict­ed use, dis­tri­b­u­tion, and repro­duc­tion in any medi­um, pro­vid­ed the orig­i­nal work is prop­er­ly cited.