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ARS Home » Southeast Area » Raleigh, North Carolina » Food Science and Market Quality and Handling Research Unit » Research » Publications at this Location » Publication #402396

Research Project: Influence of Ingredients and Processing Methods on the Safety of Fermented and Acidified Foods

Location: Food Science and Market Quality and Handling Research Unit

Title: Modeling the formulation pH of elderberry syrup with multiple weak acids

item FRAGEDAKIS, NICHOLAS - North Carolina State University
item SKINNER, CAITLIN - Former ARS Employee
item SHRINER, MILEAH - North Carolina State University
item RUINSKY, MOLLIE - North Carolina State University
item YANG, SEO YOUNG - (NCE, CECR)networks Of Centres Of Exellence Of Canada, Centres Of Excellence For Commercilization A
item WINE, ROBERT - North Carolina State University
item JOHNSTON, LYNETTE - North Carolina State University
item Breidt, Frederick

Submitted to: Journal of Food Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/23/2023
Publication Date: 8/4/2023
Citation: Fragedakis, N., Skinner, C.R., Shriner, M., Ruinsky, M., Yang, S., Wine, R.P., Johnston, L., Breidt, F. 2023. Modeling the formulation pH of elderberry syrup with multiple weak acids. Journal of Food Science. 88:3373-3383.

Interpretive Summary: Buffer modeling is a new technology that can be used to make computer models of the ingredients in acidic foods. Using these models, the pH of food ingredient mixtures can be predicted. To demonstrate the utility of this method, the ingredients of an elderberry syrup were analyzed to generate buffer models of individual and mixed ingredients. It was found that the models could accurately predict the measured pH of most of the elderberry syrup mixtures tested. Models also were used to measure the total pH impact of individual ingredients, which was defined as a value called tBeta. This technology may be useful for food companies to develop new product formulations that are safe and meet required pH values.

Technical Abstract: The objective of this work was to develop methods to assess the influence of the ingredients of an acidified elderberry syrup on product pH.Ameasure of total ingredient buffering (tBeta) was defined as the area under the buffer capacity curve of a food mixture or ingredient for pH 2–12. Citric acid (1% w/v), elderberry juice (75%v/v), andmalic acid (0.75% w/v) had greater buffering (tBeta values of 15.33, 12.00, and 10.95, respectively) than ascorbic acid (0.75%) or lemon juice (3% v/v) (tBeta of 5.74 and 3.30, respectively). All other ingredients, including added spices (=1% each) and honey (25% w/v), had tBeta values <2. The observed pH for the syrup mixture (pH 2.67) was within 0.11 pH units of the predicted pH based on combined buffermodels of the acid and low acid ingredients (pH 2.78) usingMatlab software. A total of 16 model syrup formulations containing elderberry juice with mixed acids (malic, acetic, and ascorbic) and having pH values between 3 and 4 were prepared. The pH values of the formulations were compared to predicted values from combined buffer models of the individual ingredients. Regression analysis indicated an excellent fit of the observed and predicted pH data, with a root mean square error of 0.076 pH units. The results indicated that buffer models may be useful for in silico estimates of how the ingredients in acid and acidified foods may influence pH, thus aiding in product development and safety assessments.