Sea buckthorn berries could join natural preservative club
(Hippophae rhamnoides) could inhibit the oxidation of
unsaturated fatty acids in processed meats, boosting shelf life,
suggests new research.
The antioxidant-rich extracts were found to be stable after cooking and maintained the quality of chicken and turkey meat after six days of storage, report the scientists from the Estonian University of Life Sciences in the journal Food Chemistry. "It is safe to say that the processing residue of sea buckthorn juice is a good functional supplement to mechanically deboned meat (MDM) or hand deboned meat (HDM) products, guaranteeing inhibition of the oxidation of fatty acids as well as enriching the meat products with plant-derived health-beneficial polyphenols," wrote lead author Tonu Pussa. "In addition, the optimal two per cent supplement of berry powder does not deteriorate the organoleptic properties like taste, flavour or texture of the patties prepared from the poultry MDM." Extracts from the berry, previously reported to possess heart health benefits, could be a natural alternative to artificial additives, such as like butylhydroxyanisole (BHA) and butylhydroxytoluene (BHT). According to a 2003 report by Frost and Sullivan, the synthetic antioxidant market is in decline, while natural antioxidants, such as herb extracts, tocopherols (vitamin E) and ascorbates (vitamin C) are growing, pushed by consumer desire acceptance and easier market access. Pussa and co-workers explain that the combination of higher levels of haemoproteins and polyunsaturated fatty acids (PUFAs) in MDM increases the chemical and biochemical oxidation of the fatty acids, which can adversely affect the taste and aroma of the meat, as well as producing potentially mutagenic and carcinogenic derivatives of PUFAs. "Oxygen which is bound to the meat mass and enzymes as well as heme released due to extensive stress and aeration during mechanical grinding catalyse peroxidation of the polyunsaturated fatty acids (PUFA) and hence accelerate the oxidative deterioration of the MDM," explained the researchers. They used the juice-free solid residue of sea buckthorn berries to produce extracts for use as preservatives in the meat. The extracts, containing mostly flavonols, were added at one, two and four per cent concentrations to MDM chicken and turkey. Using the 2-thiobarbituric acid reactive substances (TBARS) test as a measure of oxidation, Pussa and co-workers report a dose-dependent inhibition of the oxidation of unsaturated fatty acids in both meats. During storage, about 50 per cent of the antioxidants were lost in the turkey from oxidation, while a much smaller loss was observed in the case of chicken MDM. "The concentration of two per cent is probably optimal for the sea buckthorn supplement in both chicken and even in the highly oxidated turkey MDM," wrote the researchers. "A lower content of polyphenols is not sufficient to guarantee complete inhibition of the fatty acid oxidation and leaving of part of the added antioxidant polyphenols still in the composition. A still higher content of the plant material may reduce the organoleptic properties of the patties made from the MDM." Health appeal Recently, scientists form Finland reported that regular consumption of sea buckthorn berries reduced levels of a protein that is associated with inflammation, diabetes and heart disease. The study, published in the European Journal of Clinical Nutrition (doi: 10.1038/sj.ejcn.1602831), potentially added sea buckthorn berries to the list of antioxidant fruits, including pomegranate, guarana, mangosteen, noni berries, goji berries and blueberries, which are increasingly seen by food and beverage makers as up and coming ingredients. Moreover, in 2006 scientists in India reported a new extraction method for sea buckthorn berries giving a juice rich in vitamin C, polyphenols and flavonoids. The research, published in the Journal of the Science of Food and Agriculture (Vol. 86, pp. 2345-2353) reported using continuous high speed centrifugation (spinning) to separate the juice and the solid sludge the resulting juice retains more than 40 per cent of polyphenols, 50 per cent of flavonoids and 70 per cent of vitamin C present in the pulp of the red berries. Source: Food Chemistry (Elsevier) Volume 107, Pages 714-721, doi: 10.1016/j.foodchem.2007.08.090 "Inhibition of lipid oxidation and dynamics of polyphenol content in mechanically deboned meat supplemented with sea buckthorn (Hippophae rhamnoides) berry residues" Authors: T. Pussa, R. Pallin, P. Raudsepp, R. Soidla, M. Rei