Biosynthesis of agar in red seaweeds: A review

Lee, Wei-Kang; Lim, Yi-Yi; Leow, Adam Thean Chor; Namasivayam, Parameswari; Abdullah, Janna Ong; Ho, Chai Ling

doi:10.1016/j.carbpol.2017.01.078

Cited by 168 publications

(67 citation statements)

References 81 publications

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“…The biosynthetic pathway of agar is less explored and the genes involved have yet been elucidated47. In this study, we identified a number of putative genes which could be involved in the biosynthesis of agar precursors from G. changii and G. salicornia (Fig.…”

Section: Resultsmentioning

confidence: 99%

Transcriptome profiling of sulfate deprivation responses in two agarophytes Gracilaria changii and Gracilaria salicornia (Rhodophyta)

Lee

Namasivayam

Abdullah

et al. 2017

Sci Rep

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Seaweeds survive in marine waters with high sulfate concentration compared to those living at freshwater habitats. The cell wall polymer of Gracilaria spp. which supplies more than 50% of the world agar is heavily sulfated. Since sulfation reduces the agar quality, it is interesting to investigate the effects of sulfate deprivation on the sulfate contents of seaweed and agar, as well as the metabolic pathways of these seaweeds. In this study, two agarophytes G. changii and G. salicornia were treated under sulfate deprivation for 5 days. The sulfate contents in the seaweed/agar were generally lower in sulfate-deprivated samples compared to those in the controls, but the differences were only statistically significant for seaweed sample of G. changii and agar sample of G. salicornia. RNA sequencing (RNA-Seq) of sulfate-deprivated and untreated seaweed samples revealed 1,292 and 3,439 differentially expressed genes (DEGs; ≥1.5-fold) in sulfate-deprivated G. changii and G. salicornia, respectively, compared to their respective controls. Among the annotated DEGs were genes involved in putative agar biosynthesis, sulfur metabolism, metabolism of sulfur-containing amino acids, carbon metabolism and oxidative stress. These findings shed light on the sulfate deprivation responses in agarophytes and help to identify candidate genes involved in agar biosynthesis.

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Section: Resultsmentioning

confidence: 99%

Transcriptome profiling of sulfate deprivation responses in two agarophytes Gracilaria changii and Gracilaria salicornia (Rhodophyta)

Lee

Namasivayam

Abdullah

et al. 2017

Sci Rep

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“…Being a sulfuric acid ester of a linear galactan, agar is soluble in hot water but insoluble in cold water. Agar refers to neutral polysaccharide with repeated D-galactose and 3,6-anhydro-L-galactose units joined by β-1,3-and α-1,4-glycosidic bonds, respectively [45] with possible occurrence of sulphate, methoxyl, and/or pyruvate substituents at various positions in the polysaccharide chain [46]. Agar from Gelidium has melting & gelling temperature between 80-90°C and 28-31°C whereas agar extracted from Gracilaria has gelling and melting temperatures between 29-42°C and 76-92°C respectively Agar in red algal cell wall is believed to provide resistance to pathogens [47] Agar Figure-4.…”

Section: Source and Propertiesmentioning

confidence: 99%

Seaweed Based Bio Polymeric Film and Their Application: A Review on Hydrocolloid Polysaccharides

Parveen¹,

Maraz²,

Mahmud³

et al. 2019

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The objective of this paper is to discuss the potential of seaweed based polysaccharides as biopolymer in the formulation development and its allied applications. This review is an attempt to describe possible ways to produce environmental friendly bio packaging, bio textile, bio medicinal stuffs that can be at least slightly decomposed to smaller substances by the living organisms from marine algae. The main applications in food packaging and biomedicine are briefly mentioned followed by tentative applications in the domains of packaging, textile, paper and medical textiles which are described. This review also suggests new perspectives for future studies with these polymers.

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“…Jenis rumput laut yang banyak digunakan sebagai bahan baku untuk pengolahan agar-agar adalah Gelidium sp., Gracillaria sp., Hypnea sp., Plerodadia sp., Acanthopelus sp., dan Ceramium sp. (Lee et al 2017).…”

Section: Pendahuluanunclassified

Formulation of Hydrocolloid-Agar, Sucrose, and Acidulant on Jam Leather Product Development

Ramadhan

Trilaksani

2017

Jurnal PHPI

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AbstrakPenggunaan agar-agar tepung sebagai texturizer dalam pemanfaatan jambu biji merah (Psidium guajava L.) sebagai single selai lembaran menjadikan produk selai lebih praktis dalam penyajiannya. Penelitian ini bertujuan untuk menentukan formulasi sukrosa, asam sitrat (acidulant) dan agar-agar tepung terbaik pada pembuatan selai lembaran. Metode penelitian yang digunakan adalah optimasi dan formulasi sukrosa, asam sitrat dan agar-agar dengan kosentrasi berbeda dalam pembuatan selai lembaran. Pengujian fisikokimia dan sensori dilakukan untuk menentukan formula selai lembaran terbaik, selain itu metode bayes digunakan untuk menentukan optimasi formula terpilih. Formulasi dan pengujian diperoleh selai jambu biji lembaran dengan konsentrasi Acidulant asam sitrat (0,02%, 0,04%, 0,06%), sukrosa (70%, 80%, 90%, 100%) dan agar-agar tepung (0,7%, 0,8%, 0,9%, 1,0%, 1,1%, 1,2%), memiliki nilai pH 3,63-3,90; kadar gula 34,68-35,76 g/100 g; intensitas warna L*, a*, b* dengan perbedaan warna (ΔE*) 37,88-53,97; kadar serat 1,01%-1,59%; dan nilai aw 0,852-0,893. Sifat rheology selai lembaran untuk profil tekstur hardness, cohesiveness, springiness, adhesive force, dan gumminess juga menunjukkan nilai yang signifikan dengan penambahan tepung agar. Hasil uji Bayes, produk terpilih merupakan formulasi terbaik dengan penambahan gula 90%, asam sitrat 0,04% dan agar-agar tepung 0,9%. Selai lembaran terpilih menghasilkan model persamaan umur simpan Arrhenius ln k = 20,222-6660,6 (1/T) dan memiliki angka kecukupan gizi dengan menyumbangkan energi total 45 kkal, lemak 0%, karbohidrat 9%, protein 2% dan serat pangan 3%.Kata kunci: agar-agar tepung, profil tekstur, rheologi, selai jambu biji lembaran AbstractTallying agar powder as a texturizer in guava single sheet jam instigate the product more convenience to consumed. The aims of this research were to determine the best concentration of sucrose, citric acid and agar powder to form a good quality guava jam slice. The research method are optimization and formulation of sucrose, citric acid and agar-agar on making guava jam single sheets product. Physochemical and sensory tests were performed to reveal the best formulation of guava jam slice and the Bayes method used to determine the optimization of the selected formula. Based on the results of formulation and analysis, it was obtained that the guava jam slice with Acidulant concentration (0.02%, 0.04%, 0.06%), sucrose (70%, 80%, 90%, 100%) and agar powder (0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%) had pH 3.63-3.90, sugar content 34.68 g/100 g -35.76 g/100 g, color intensity L*, a*, b* with ΔE* value was 37,88-53,97, fiber content 1.01% -1.59%, and water activity 0.852-0.893. Rheology properties for texture profile (hardness, cohesiveness, springiness, adhesive force, and gumminess) also showed significant value with agar powder formulation. Based on the Bayes test and hedonic test, it was found that the best formula was for guava jam slices with the addition of 90% sucrose, citric acid 0.04% and agar powder 0.9%. From the best formula, it wa...

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Biosynthesis of agar in red seaweeds: A review

Cited by 168 publications

References 81 publications

Transcriptome profiling of sulfate deprivation responses in two agarophytes Gracilaria changii and Gracilaria salicornia (Rhodophyta)

Transcriptome profiling of sulfate deprivation responses in two agarophytes Gracilaria changii and Gracilaria salicornia (Rhodophyta)

Seaweed Based Bio Polymeric Film and Their Application: A Review on Hydrocolloid Polysaccharides

Formulation of Hydrocolloid-Agar, Sucrose, and Acidulant on Jam Leather Product Development

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