The application of cranberry in the production and quality of fresh dairy products

The antioxidant activity of an ethanol extract prepared from cranberries was investigated using the oxygen radical absorbance capacity (ORAC) assay, as well as in a model food emulsion representative of dairy-based emulsions. The cranberry extract exhibited 348.31 ± 33.45 Trolox equivalents (TE)/g in the hydrophilic ORAC assay. In the model food emulsion consisting of 25% lipid stabilized by sodium caseinate, the extract was readily incorporated at the homogenization step until a pH of 5.6 was attained without causing emulsion destabilization. Under thermal conditions (50ºC), the lag phase prior to propagation of conjugated dienes (CD) in all cranberry emulsions at pH 5.6 was significantly extended relative to untreated controls (P < 0.05). The formation of secondary lipid oxidation products (hexanal and pentanal) in sunflower oil emulsions became significantly reduced (P < 0.05), but only after 64 hours of incubation. In contrast, the development of hexanal and pentanal in butterfat emulsions were significantly reduced (P < 0.05) over the entire incubation period. Increasing the level of cranberry extract in all emulsions beyond a final pH of 5.6 had an adverse effect on emulsion stability, and this was met with a drop in oxidative protection. The acidity of the cranberry extract made it well-suited for use in a fresh cream cheese product, which requires the production of acid during manufacture. The cranberry extract was homogenized into a cream cheese premix consisting of milk and cream until a pH of 5.6 was reached. Cheese produced from 1.18 g extract/100 g premix had a light pink color that remained stable over 50 days of storage at 4ºC. The cheese curd was found to retain over 98% of phenolics from the extract after separation of the whey. The level of CD and the peroxide value in the final product were significantly lower (P < 0.05) as compared to the untreated control cream cheese, after two weeks of storage at 4ºC. This research shows for the first time that a cranberry extract rich in bioactives can provide color and flavor to fresh dairy products while also acting as a useful preservation agent.Land and Food Systems, Faculty ofGraduat

Studies on Mitigating Lipid Oxidation Reactions in a Value-Added Dairy Product Using a Standardized Cranberry Extract

A standardized whole cranberry extract (WCE) was used to stabilize a model sunflower-casein emulsion prototype for future formulation activities with a fresh cream cheese product. The WCE contained total organic acids (20% w/w) and polyphenols (5%), the latter consisting of total anthocyanins (10%, w/w) and proanthocyanidins (12% w/w). Antioxidant capacity of the WCE was determined by ORAC, (hydrophilic ORAC = 348.31 ± 33.45 µmol of Trolox equivalents/g; lipophilic ORAC = 11.02 ± 0.85 µmol of Trolox equivalents/g). WCE was effective at stabilizing the model emulsion at a level of 0.375% (w/w), yielding a final pH of 5.6. Generation of initial lipid peroxidation products, hexanal and pentanal was inhibited by 92.4% ± 3.9% and 66.6% ± 5.3% (n = 3), respectively, when emulsions containing WCE were incubated at 50 °C for 90 h. This information was useful for formulating a fresh cream cheese product containing WCE to produce value-added potential and good self-life. The standardized WCE gave a final pH of 5.6 for the cheese premix and also significantly (P < 0.05) lowered both the PV and CD after 28 and 21 days at 4 °C storage, respectively, compared to untreated control. We conclude that there are important functional role(s) for cranberry constituents when presented as a standardized ingredient for producing value-added, stable fresh dairy products.Land and Food Systems, Faculty ofReviewedFacult