Egyptian weed may offer novel hydrocolloid for foods

The plant could offer a new hydrocolloid with interesting functional properties, and be a locust bean gum (LBG) alternative according to results presented in the journal Food Hydrocolloids .

"[This study] has revealed that hydrocolloid from leaves of C. olitorius (HLC) exhibited unique rheological behaviour such as a strong synergy with kappa-carrageenan in relation to gel strength," wrote Eiji Yamazaki, Osamu Kurita, and Yasuki Matsumura from the Mie Prefectural Science and Technology Promotion Center.

"The synergistic effect on mixed gel made with kappa-carrageenan was different from mixed gels with LBG.

The difference implies that HLC could not only be an alternative to LBG in many applications, but may introduce new functions to kappa-carrageenan and other hydrocolloids.

"Thus C. olitorius is an interesting source of hydrocolloid though further investigation should be done in order to fully explore the potential of HLC," they added.

The findings may be welcomed since the cost of nearly all hydrocolloids have increased in the last year due to rocketing energy, raw material and transportation costs, according to hydrocolloid information service IMR's Quarterly Review.

Thickeners, along with emulsion stabilisers, suspending agents, gelling agents, thickeners, fibre sources, mouthfeel improvers, fat replacers and processing aids all come under the umbrella of hydrocolloids.

This market has grown significantly in the past 20 years in parallel to an increasingly complex food processing industry.

The food industry's most frequently used hydrocolloids include: agar, alginates, arabic, carrageenan, Carboxy Methyl Cellulose (CMC), gelatin, konjac flour, locust bean gum (LBG), Methyl Cellulose and hydroxypropyl Methyl Cellulose (MC/HPMC), microcrystalline cellulose (MCC), pectin, starch and Xanthan.

A potential new member of this team, if further research backs up the promising early studies, could be hydrocolloid from leaves of C. olitorius .

Promising data Yamazaki, Kurita, and Matsumura used an ammonium sulphate fractionation technique to extract the hydrocolloid from the plant.

A yield of six per cent was obtained, with the carbohydrate, anhydrouronic acid, protein, and moisture content of 62.2, 35.3, 5.5, and 16.1, respectively.

Mixed gels were prepared from kappa-carrageenan and HLC (one per cent) and the gel strength measured.

The gel strengths were compared to a kappa-carrageenan-LBG gel.

"T he synergistic effects of mixed gels made from kappa -carrageenan and LBG at the composition range around 90/10 were apparently lower than that of the kappa -carrageenan and HLC in the same composition range ," wrote the researchers. "

It meant that the addition of HLC was able to improve the kappa -carrageenan gel strength at the lower concentration than that of LBG. "

Source: Food Hydrocolloids Volume 22, Issue 5, Pages 819-825 "Hydrocolloid from leaves of Corchorus olitorius and its synergistic effect on ?-carrageenan gel strength" Authors: Eiji Yamazaki, Osamu Kurita, Yasuki Matsumura