The relationship between SPAD-501 meter readings (SPAD) and total chlorophyll content (TCHL) was evaluated for `Delicious' apple (Malus domestica Borkh.) leaves grown in various environments. Regression models were developed between SPAD and TCHL for each of six separate experiments and were evaluated for statistical coincidence. SPAD was linearly related in a positive manner to TCHL in five of the six experiments; however, models differed between experiments, particularly between field- and greenhouse-grown trees. Thus, the relationship between SPAD and TCHL must be determined for each experiment.
Abstract
A regression equation is presented to relate concentration of carotenoids in dehydrated Capsicum powders from µg/g to industry accepted Lovibond red units. Hydration of powders prior to acetone extraction increased removal of pigments from the powders and extracted brown components often present in the powders. The procedure for total carotenoid extraction from hydra ted Capsicum powders and estimation of brown, water-soluble components is described.
Lingonberries have been shown to contain high antioxidant activity. Fruit from different cultivars of lingonberry (Vacciniumvitis-idaea L) were evaluated for fruit quality, antioxidant activity, anthocyanin and phenolic contents. The fruit soluble solids content (SSC), titratable acids (TA), antioxidant capacity, anthocyanin and phenolic contents varied with cultivars. The SSC ranged from 12.9% to 16.9%, the TA ranged from 0.31% to 0.41% and the ratios of SSC/TA ranged from 35.37 to 51.21. Lingonberries contain potent free radical scavenging activities for DPPH·, ROO·, ·OH and O .- 2 radicals. The oxygen radical absorbance capacity (ORAC) values from acetone extraction of lingonberries ranged from 58.5–223.6 μmol of Trolox equivalents (TE)/g fresh berries. The ED50 values for DPPH-radical scavenging ranged from 5.91–11.77 mg fresh weight. The DPPH-radical scavenging activity correlated with ORAC values with a R 2 of 0.8009. ESR spectrum showed that 50 mg·mL-1 of lingonberry extract decreased ·OH radicals by 83% and O .- 2 radicals by 99%. Cyanidin 3-galactoside was the most dominant anthocyanin and contributed the most antioxidant activity in lingonberries. The antioxidant properties of lingonberries may play an important role in protecting cells against the oxidative damage caused by free radicals.
methanol. Methanol destroys cell membranes and simultaneously dissolves the anthocyanins ( Shahidi and Naczk, 2003 ). Ethanol extraction gave the highest yield of pigment and polyphenols (colorants) in dragon fruit with 7.7, and acetone extraction gave the
immediately, using acetone extraction ( Arnon, 1949 ). In plants which did not grow, the second and third pairs were sampled and then the second plant was used. About 100–200 mg of the leaf tissue without the midvein were ground in 20 mL of 80% acetone using a
Instruments, Inc., Westbury, NY). The homogenized samples from the acetone extraction were then centrifuged at 14,000 g n for 20 min at 4 °C. The supernatants were transferred to vials, stored at –80 °C, and later used for ORAC analysis after suitable