Low-grade apples may give high-grade pectin for industry
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.
The functionality of the pectin is dictated by the chemical fine structure, and the majority of the pectins used currently come from citrus peel and apple pomace.
Alternative sources for the ingredient have been mooted, ranging from sunflower seeds, potato peel, banana, cocoa husks, mango peel, and pumpkin, but the industry thinks that such sources will not rival citrus and apple.
"Real alternative sources for pectin production do not exist," Hans-Ulrich Endress, the secretary general for the International Pectin Producers Association (IPPA), told FoodNavigator last year.
According to findings published in Food Chemistry, the yield of pectin from low quality ‘Golden Delicious’ apple fruit was 16 per cent, “which was similar to that reported by [other researchers in 2005] for pectins from apple pomace”.
Prices and viable volumes
With the price of hydrocolloids increasing, and pectin no exception, there exists a financial incentive to explore alternatives. However, Dennis Seisun from IMR International, a consultancy that publishes the Quarterly Review of Food Hydrocolloids, said last year: "The issue with alternative sources is extracting pectin in commercially viable volumes."
The Mexican researchers appear to allay concerns over viable volumes, noting that northern Mexico provides over 50 per cent of the country’s apple production, and an important part of this being considered to be low quality. Such fruit “is destined for industrial processing or is not picked up in local orchards due unprofitability of the low prices market”.
With this in mind, the researchers, led by Agustin Rascon-Chu from the Centro de Investigacion en Alimentacion y Desarrollo, Unidad Cuauhtemoc, used a simple extraction method (citric acid followed by ethanol precipitation) to produce pectin with a high galacturonic acid content of 65 per cent. The pectin gelled 60 per cent fructose at pH 2.7.
“The pectin concentration significantly increased the hardness and adhesiveness of the gels,” added the researchers. “Therefore, the pectin recovered could be used as food additive to texturise or stabilize different food products.
“The results demonstrate that low quality apple fruit is a suitable raw material for industrial pectin extraction,” they concluded.
Source: Food Chemistry Volume 116, Issue 1, Pages 101-103"Pectin from low quality ‘Golden Delicious’ apples: Composition and gelling capability" Authors: A. Rascon-Chu, A.L. Martinez-Lopez, E. Carvajal-Millan, N.E. Ponce de Leon-Renova, J.A. Marquez-Escalante, A. Romo-Chacon