Determination of some quality criteria in non-alcoholic beverages

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Thesis Type: Postgraduate

Institution Of The Thesis: Gazi University, Sağlık Bilimleri Enstitüsü, Turkey

Approval Date: 2023

Thesis Language: Turkish

Student: Hanife ALTINSOY

Supervisor: Burak Demirhan

Open Archive Collection: AVESIS Open Access Collection

Abstract:

In this study, the aim was to determine quality criteria such as pH, Brix, electrical conductivity, total phenolic content, and the amount of furfural compounds in fruit juices. As part of the study, 4 different fruit juice samples (pineapple, apple, pomegranate, grape) and turnip juice sample from seven different brands (A, B, C, D, E, F, G), totaling 100 samples available in Ankara, were analyzed. The analysis of furfural compounds in the fruit juices was carried out using high-performance liquid chromatography with a diode array detector (HPLC-DAD). The analysis of 5-hydroxymethylfurfural (5-HMF) and furfural provided linear results over a wide concentration range (5-HMF: R2>0.999; furfural: R2>0.999). The average recoveries of 5-HMF and furfural were found to be 109.1% and 98.5%, respectively. The limit of detection (LOD) and the limit of quantification (LOQ) values for 5-HMF were determined as 0.0153 mg/L and 0.0463 mg/L, respectively. These values were determined as 0.0136 mg/L and 0.0413 mg/L for furfural. The mean 5-HMF values in fruit juices were found as 0.0540.034 mg/L, 0.0520.056 mg/L, 0.6610.451 mg/L, 0.0920.047 mg/L for pineapple, apple, pomegranate and grape juices, respectively. The amount of 5-HMF in turnip juice was determined as 0.0030.003 mg/L. The mean furfural values in fruit juices were found as 0.0070.004 mg/L, 0.0060.008 mg/L, 0.0870.059 mg/L and 0.0120.006 mg/L for pineapple, apple, pomegranate and grape juices, respectively. Furfural could not be detected in turnip juice. The highest total phenolic content (TPC) determined in pomegranate juice (399.87149.80 mg/L), the lowest TPC determined in pineapple juice (49.3116.54 mg/L). Other parameters such as pH, electrical conductivity, brix were generally found to compliance with the standards. The 5-HMF content is generally accepted as a quality indicator in the food industry, as it indicates overheating during processing or inadequate storage conditions. The detection of these process contaminants, which can potentially be toxic for consumer health and food safety, is of great importance.

Key Words : 5-HMF, Furfural, Total Phenolic Content, Non-Alcoholic Beverage, HPLC