Blueberry-aronia nectar is known as a rich source of anthocyanins, which are mostly destroyed during commercial storage of the product. The factors influencing the rate of degradation are connected to the oxygen protection offered by the packaging, as well as the type of anthocyanidin and the amount of glycosylated sugar. The current study was aimed to compare the stability of total anthocyanin between glass and carton packaging as well as to determine the stability of individual anthocyanin with respect to aglycone and glycosylated sugar. The degradation rate of total anthocyanin degradation rate was 22% higher in carton packaging than glass bottle. The ranking order of the stability of individual anthocyanin with respect to aglycone was as follows (from the most to least stable): cyanindin > peonidin > petunidin > malvidin = delphinidin. The ranking order of the stability of anthocyanins with respect to glycosylated sugars was as follows (from the most to least stable): glucose > galactose > arabinose. As individual anthocyanins have different degradation rates this study can be used to determine the most stable natural colorant and the most sensitive antioxidant among the anthocyanins tested.

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The dietary sources of CoQ10 and the evaluation of CoQ10 in dairy products were characterized. For quantitation of CoQ10 in food samples, 2 liquid chromatography (LC) methods with UV and mass spectrometry (MS) detections were developed. LC with UV detection was performed at 25°C on a Hyperclone ODS 5 μm 150 × 4.6 mm column with mobile phase consisting of methanol-ethanol-2-propanol (70 + 15 + 15, v/v/v). Flow rate was 1.0 mL/min. Retention time of CoQ10 was 10.9 ± 0.1 min. The method was sensitive [limit of detection (LOD) = 0.2 mg/kg], reproducible [relative standard deviation (RSD) = 3.0%), and linear up to 25 mg/kg (R > 0.999). LC/MS analysis was performed on a LUNA C18 3 μm, 150 × 4.6 mm column, using mobile phase consisting of ethanol-dioxane-acetic acid (9 + 1 + 0.01, v/v/v), flow rate was 0.6 mL/min, and the retention time of CoQ10 was 4.1 ± 0.1 min. Identification and quantitation were performed with a Finnigan-LCQ mass detector in positive atmospheric pressure chemical ionization mode. Mass spectra were obtained in selected-ion monitoring mode; molecular mass (M+H)+m/z 863.4 ± 1 was used for quantitative determination. MS detection is more sensitive than UV detection (LOD = 0.1 mg/kg), less reproducible (RSD = 4.0%), and linear in selected range. Analytical recoveries are 75–90% and depend on the ratio between the amount of fat in the matrix and the concentration of CoQ10 in the sample. Some soybean milk products were analyzed together with different cow, goat, and sheep milk products. Concentrations obtained with LC and LC/MS were compared with a few accessible results available from the literature. Concentrations varied from 0 ppm in soybean milk to nearly 2 ppm in fresh milk from local farms.

Phenylketonuria is a common metabolic disorder disease. Those affected appear normal at birth, but without treatment they develop severe psychomotor retardation. Throughout life, they must control their blood levels of phenylalanine (Phe) and consume a diet containing adequate amounts of Phe and tyrosine (Tyr). We have developed a liquid chromatographic/mass spectrometric (LC/MS) method for the quantitative evaluation of Phe and Tyr in food samples. This method takes advantage of the good separation of LC and the selective and reliable quantification provided by MS in the electrospray ionization mode. The LC/MS method is very suitable for the determination of selected amino acids in various matrixes. It is sensitive to levels as low as about 0.30 ppm for Tyr and 0.70 ppm for Phe and robust. Nearly 100 nondietary food samples were analyzed by the developed method.