Three phenolic acids, (+)catechins, chlorogenic acid, and rutin, were identified and quantified in Mamaki leaves using a liquid chromatograph-mass spectrometer technique. Concentrations of (+)catechins, chlorogenic acid, and rutin varied from 1.1 to 5.0 mg/g of Mamaki leaves as determined in the extract using 0.5% acetic acid in 90% aqueous methanol. This study also quantified total antioxidant capacity using the photochemiluminescence method, which was expressed in equivalents to ascorbic acid (AA). Mamaki teas brewed for 30 min contained total antioxidant activity (TAA) between 238 and 259 mg AA/g of tea. Mamaki teas brewed for 1 h and stored at 4 h, 1 d, and 3 d at 4 degrees C had available TAA 293, 271, 172, and 163 mg AA/g of tea leaves, respectively. The concentrations of (+)catechins and rutin in Mamaki leaves are compared to other types of popular teas. Mamaki teas contained relatively low amounts of TAA compared to green teas and Lipton teas.

This study evaluates the presence, location and production source of tetrodotoxin (TTX) in two species of pufferfish, Diodon histrix and Arothron hispidus, common to Hawaiian waters. Organs from each fish were analysed for TTX and used to isolate bacteria for evaluation of possible TTX production. Comparative analyses of extracts of fish and bacterial culture media were performed with liquid chromatography-mass spectrometry (LC-MS) and a sodium channel specific bioassay. Bacterial cultivation experiments were performed in two different growth media and bacteria were identified through sequence homology of the 16S rRNA gene. Forty-two and forty-seven distinct strains were cultivated from D. histrix and A. hispidus, respectively. However, no commonality was found between the populations of bacteria isolated from the two fish. TTX was detected only in A. hispidus and was present in the flesh, pectoral fin and kidneys, as well as the skin slime. Sixteen of the forty-seven bacterial species isolated from A. hispidus were cultivated for further evaluation of TTX production. Among these sixteen bacterial species, Vibrio harveyi strains isolated from the skin slime and kidneys of A. hispidus were found to produce TTX, being the source of TTX produced in the pufferfish.

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The functional food ingredients of apple juice can significantly change during processing, transportation, and storage, thus affecting the quality of the product. A simple and derivation‐free analytical method based on ultra‐high‐performance liquid chromatography–tandem mass spectrometry (UPLC‐MS/MS) was developed and optimized for the simultaneous determination of functional food ingredients in apple juice bought in the market. Cleanup steps and chromatographic conditions were optimized to remove interference and decrease the matrix effect. The nine target analytes were separated on an Acquity UPLC system equipped with a BEH C18 column and detected by electrospray ionization source (ESI) operating in positive subsection acquisition mode under multiple reaction monitoring (MRM) conditions. The results showed that p‐hydroxybenzoic acid, protocatechuate, caffeic acid, chlorogenic acid, epicatechin, phloridzin, hyperoside, procyanidin B2, and rutin could be sufficiently separated for content determination within 6 min. In the concentration range of 20 μg/L–50 mg/L, nine standard samples exhibited a good linear fit with correlation coefficients above .985.