In this study, the changes caused by chilling stress on some physiological parameters of pepino (Solanum muricatum Ait.) plant and the effects of ascorbic acid (100 mM) applied exogenously on these changes were examined. For this purpose, the photosynthetic pigments (chlorophyll a, chlorophyll b, total chlorophylls and carotenoids), ascorbic acid, total phenolic compounds, malondialdehyde and proline contents in leaves of pepino taken on 5 th and 10 th days were determined. As a result of chilling stress, it was found that while the photosynthetic pigments and proline contents decreased in pepino leaves, the ascorbic acid, total phenolic compounds and malondialdehyde contents increased. In plants which were subjected to pre-treatment of ascorbic acid on the 10 th day of stress, ascorbic acid and proline contents increased while a decrease was observed in malondialdehyde content, compared to stress group without pre-treated. This study may be important for explaining resistance induced by treatment of exogenous ascorbic acid in pepino exposed to chilling stress.

BackgroundThis study aimed to determine the seasonal changes of total antioxidant activity and phenolic compounds in samples taken from leaves (April, July, October) and stems (April, July, October, January) of some almond (Prunus amygdalus L.) varieties (Nonpareil, Ferragnes and Texas).ResultsIt was indicated that antioxidant activity and phenolic compounds in leaves and stems of Nonpareil, Ferragnes and Texas showed seasonal differences. Antioxidant activity IC50 of these varieties reached the highest value in April for leaves whereas in October for stems. The highest level of total phenolic compounds was in January for stems while in October for leaves.ConclusionsThese results showed that total antioxidant activity and phenolics in leaves and stems of almond varieties changed according to season and plant organ.

The purpose of this study was to investigate the effects of the pine sac beetle (Thaumetopoea pityocampa Schiff.) on the pigments (chlorophyll a, chlorophyll b and carotenoids) and total phenolic compounds in the Pinus nigra L. and Pinus brutia Ten. spread throughout the forest areas in the Boyabat District of the Sinop Province. It was found that chlorophyll a, chlorophyll b and carotenoids contents were lower on the leaves of the P. nigra and P. brutia which had pine sac beetles in comparison to those not having pine sac beetles. It was also observed that the contents of chlorophyll a and chlorophyll b were decreased on the stems of both species but there was no significant change in the contents of carotenoid. The phenolic compound levels increased in the leaves and the stems of P. nigra and P. brutia which had pine sac beetles compared to those that did not have pine sac beetles

In this study, Chara vulgaris samples were taken from Gölbaşı Lake/Adıyaman at different times (October, February, April, June). Total phenolic and pigment contents of these samples were examined. It was determined that total phenolic and pigment contents (chlorophyll a, chlorophyll b, and carotenoids) showed seasonal differences. It was detected that chlorophyll a, chlorophyll b, and carotenoids were high in June, and low in April. In addition, phenolic compounds were found to be high in February, and low in April.

Due to the short harvest season and their sensitivity to storage, the preservation of fresh mulberry fruits is a very important process. Drying is a method used to preserve mulberry fruits in the long term. In this study, response surface methodology (RSM) was applied for the optimization of hybrid drying conditions of two different sour black mulberries. The linear and interaction effects of independent parameters such as temperature (50, 60 and 70°C) and microwave power (100, 200 and 300 W) variables were determined on mulberries. Bioactive properties and energy aspects were monitored as influenced by drying conditions. According to the results increase in microwave power provided a significant decrement in the specific energy consumption (SEC) and the total anthocyanin content (TAC), while increase in the energy efficiency (ηen) and total phenolic content (TPC) for both genotypes. In all cases, statistical values showed that all drying curves of black mulberry were best described by the Logistic model. Multiple response optimization was carried out for studied parameters and it was concluded that maximum antiradical activity (ARA), TPC, TAC, ηen and minimum drying time (DT) and SEC values would be at 300 W-50 ºC (desirability=0.842) and 300 W-66.5 ºC (desirability=0.744), for Morus nigra 1 (MN1) and Morus nigra 2 (MN2), respectively. According to the finding, the greatest TPC, ARA, TAC, DT, SEC and ηen were determined as 20.10 mg GAE/g, 86.00%, 456 mg/kg, HIGHLIGHTS• Sour black mulberries were evaluated in terms of drying method.• Logistic model showed the best fitting performance.• Specific energy consumption increased with increase in microwave power.

Seasonal change of total carbohydrate contents in samples taken from leaves and stems of almond varieties was investigated. Carbohydrate contents in the leaves and stem of all varieties showed seasonal differences. The highest carbohydrate content in the leaves and stem of all varieties was found in April, and January, respectively. The lowest carbohydrate content in the leaves of Nonpareil was found in July, that of Ferragnes and Texas in October. The lowest level of carbohydrate content in the stem of all varieties was found in July. DOI: http://dx.doi.org/10.3329/bjb.v43i2.21677 Bangladesh J. Bot. 43(2): 223-225, 2014 (September)