An optimal saponification and extraction method to determine carotenoids in avocado.

Quantification of carotenoids in avocado fruit is a great challenge due to their co-extraction with high-oil concentration and the inherent nature of carotenoids to degrade and undergo cis/trans photoisomerization with prolonged extraction times and high temperatures. The study provides an optimised and validated methodology for quantification of carotenoids in the high-oil avocado matrix, with > 93% recovery of all carotenoids tested being significantly greater than previously published. Saponification with 15% KOH for 60 min was optimal for the avocado matrix. For the first time, this study identified that soap, produced during the saponification reaction, resulted in a significant reduction of carotenoid content from the avocado matrix, due to the production of micelles. A significantly higher carotenoid content (3.58 versus 2.0 mg/100 g DW) was able to be extracted after saponification with acidified phosphate buffer, instead of water as reported previously. Carotenoid profiles of five avocado cultivars were identified and quantified.

Temperature and Maturity Stages Affect Anthocyanin Development and Phenolic and Sugar Content of Purple-Pericarp Supersweet Sweetcorn during Storage.

Purple-pericarp sweetcorn (PPS) is a novel product, requiring both purple pigment development and maintenance of sweetness. Storage period and temperature had a profound impact on total anthocyanin accumulation (TAC) and sugar content. While TAC remained relatively unchanged during 14-day storage at 4 °C, the first recorded observation of continuing accumulation of anthocyanin and phenolic compounds was concurrent with an increase in purple pigment coverage across the surface of the kernel at 23 °C. TAC in PPS significantly increased, doubling after 14 days at 23 °C. Anthocyanin concentration and kernel coverage were also affected by harvest maturity. The results indicated that biosynthesis of anthocyanins is still occurring during postharvest storage of PPS. A significant decline in sugar concentration was also observed during storage with a greater decline at 23 °C. As anthocyanin accumulation and maintaining sweetness are important factors for sweetcorn, identifying storage temperatures that optimize both quality criteria are required.

Optimisation of extraction procedure and development of LC-DAD-MS methodology for anthocyanin analysis in anthocyanin-pigmented corn kernels.

An ultra-high-performance liquid chromatography-diode array detector-mass spectrometry method was developed for characterisation and quantification of anthocyanin components in complex corn-kernel matrices. The anthocyanin profiles and total anthocyanin content (TAC) of mature seeds of five types of anthocyanin-pigmented corn were reported. Internal standard was used to validate the efficiency of extraction and optimise the liquid extraction procedure for anthocyanins. A total of eighteen anthocyanins were identified and quantified. Cyanidin-based glucosides were the major pigments of purple-pericarp sweetcorn (75.5% of TAC) and blue-aleurone maize (91.6%), while pelargonidin-based glucosides composed the main anthocyanins of reddish-purple-pericarp sweetcorn (61.1%) and cherry-aleurone maize (74.6%). Importantly, previous studies reported the presence of acetylated and succinylated anthocyanins in corn kernels; these compounds were found to be artefact pigments, generated during the extraction process. These crucial findings provide the correct anthocyanin profiles of pigmented corns, and emphasise the importance of using acidified solutions for the extraction of corn-based anthocyanins.

Anthocyanin composition and changes during kernel development in purple-pericarp supersweet sweetcorn.

The current study reports the anthocyanin profile of purple 'supersweet' sweetcorn, recently developed from purple Peruvian maize, and the effect of kernel maturity on anthocyanin accumulation. Twenty anthocyanin compounds, consisting of cyanidin-, peonidin-, and pelargonidin-based glucosides, were identified and quantified in purple- and reddish-purple-pericarp sweetcorn accessions. For the first time, four isomers of cyanidin-3-malonylglucoside, four isomers of pelargonidin-3-malonylglucoside and two to three isomers each of cyanidin-3-dimalonylglucoside, peonidin-3-malonylglucoside and pelargonidin-3-dimalonylglucoside, were identified in the new pigmented sweetcorn. While cyanidin-based glucosides predominated in the purple-pericarp accession, pelargonidin-based glucosides predominated in the reddish-purple accession. Total anthocyanin concentration increased significantly (p < 0.05) during the optimum sweetcorn eating period (23 to 28 DAP) and continued to increase as the kernels further matured (>28 DAP). As kernels continued to mature, pigment coverage across the pericarp progressively increased from a small spot at the stigma end of the kernel, to gradually spreading over the entire kernel.

The effect of sustained heavy exercise on the development of pulmonary edema in trained male cyclists.

To determine whether intense, prolonged activity can induce transient pulmonary edema, eight highly trained male cyclists (mean +/- S.D.: age, 26.9 +/- 3.0 years; height, 179.9 +/- 5.7 cm; weight, 76.1 +/- 6.5 kg) performed a 45-min endurance cycle test (ECT). V(O2,max) was determined (4.84 +/- 0.4 L min(-1), 63.7 +/- 2.6 ml min(-1) g(-1)) and the intensity of exercise for the ECT was set at 10% below ventilatory threshold (approximately 76% V(O2, max) 300 +/- 25 W). Pre- and post-exercise pulmonary diffusion (DL(CO)) measurements and magnetic resonance imaging of the lung were made. DL(CO) and pulmonary capillary blood volume (VC) decreased 1h post-exercise by 12% (P = 0.004) and 21% (P = 0.017), respectively, but no significant change in membrane diffusing capacity (DM) was found. The magnetic resonance scans demonstrated a 9.4% increase (P = 0.043) in pulmonary extravascular water 90 min post-exercise. These data support the theory that high intensity, sustained exercise in well-trained athletes can result in transient pulmonary edema.