Golden apple extracts eyed as novel pectin source
exploring the potential of ambarella peel as a source of pectin,
and could offer industry a novel ingredient with new properties.
Extracts from the tropical fruit, also known as golden apple (Spondias cytherea), were comparable to pectin from lime, report scientists from Cameroon's University of Yaounde I and Ministry of Scientific Research and Innovation, and France's INRA (UR1268). The research, published in the journal Food Chemistry, taps into the growing trend for alternative and novel sources of pectin, highlighted by an increasing number of studies looking at extracting pectin from sources such as sugar beet, mango, pumpkin and squash. The functionality of pectin is dictated by the chemical fine structure, and the majority of the pectin used currently comes from citrus peel and apple pomace. Other sources of the ingredient have remained largely unexploited because of certain undesirable structural properties. The researchers investigated the potential of ambarella peels to offer pectin for the food industry. Three types of extraction media were used - hydrochloric acid (HCl), deionised water, or oxalic acid/ammonium oxalate (OAAO) - to extract the pectin from dried alcohol-insoluble residues (AIR) of ambarella peels. The researchers report that the peels are a rich source of pectin, with yields up to 30 per cent of the AIR reported. Depending on the extraction method used, uronic acid contents vaired from 557 to 727 mg per g dry weight, the degree of methylation ranged from 50 to 58 per cent, and the molar masses were in the range 263,000-303,000 g/mol. "Since molar mass and degree of methylation are important parameters in gel-breaking strength, OAAO ambarella pectins could be useful as food additives," wrote the authors, led by B.B. Koubala. The researchers added that the ambarella pectin compared well to lime pectin extracted under the same conditions, thereby "indicating their commercial significance". Koubala and co-workers confirmed that work was ongoing; with study currently focussing on the rheological properties of ambarella peels pectin gels. Researchers from Denmark and England recently highlighted the possibilities of this ingredient and proposed that 'designer' pectin will become increasingly common in the future (Trends in Food Science & Technology, Vol. 17, pp. 97-104). The ingredient, with worldwide production estimated at 35,000 tonnes a year, is currently widely used as gelling agents in jams, confectionary, and bakery fillings, and stabilisers in yoghurts and milk drinks. Source: Food Chemistry Volume 106, Issue 3, Pages 1202-1207, doi:10.1016/j.foodchem.2007.07.065 "Physicochemical properties of pectins from ambarella peels (Spondias cytherea) obtained using different extraction conditions" Authors: B.B. Koubala, L.I. Mbome, G. Kansci, F. Tchouanguep Mbiapo, M.-J. Crepeau, J.-F. Thibault and M.-C. Ralet