Consuming food that is rich in antioxidants reduces the risk of developing chronic diseases and oxidative stress. Fruits and vegetables are an excellent source of substances with antioxidant and pro-health properties. Such raw materials, characterized by a high content of polyphenolic compounds and antioxidant capacity, include pear fruits. In this study, the concentrations of bioactive compounds, as well as the antioxidant, anti-inflammatory, and antiproliferative activity in fruits of five selected pear cultivars were determined and compared. LC–MS and UPLC–PDA methods were used to determine the polyphenolic, carotenoid, chlorophyll, and triterpenoid profiles and content, and the antioxidant activity was analyzed using DPPH and ferric-reducing ability of plasma (FRAP) tests. The anti-inflammatory activity was determined against COX-1 and COX-2 enzymes. The cytotoxic activity of the test compounds was assessed against six tumor cell lines. The results showed that the major group of phenolic compounds in all cultivars was phenolic acids. In the group of chromoplastic pigments, chlorophyllide a and 9-cis-β-carotene were the major compounds, while in the triterpene group, ursolic acid was dominant. The antioxidant potential correlated with the content of polyphenols and carotenoids, and was the strongest for the ‘Radana’ cultivar. The highest antiproliferative activity in all varieties was established for bladder cancer.
1 January 2014 in Journal of Clinical Biochemistry and Nutrition
Strawberries contain anthocyanins and ellagitanins which have antioxidant properties. We determined whether the consumption of strawberries increase the plasma antioxidant activity measured as the ability to decompose 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) in healthy subjects. The study involved 10 volunteers (age 41 ± 6 years, body weight 74.4 ± 12.7 kg) that consumed 500 g of strawberries daily for 9 days and 7 matched controls. Fasting plasma and spot morning urine samples were collected at baseline, during fruit consumption and after a 6 day wash-out period. DPPH decomposition was measured in both deproteinized native plasma specimens and pretreated with uricase (non-urate plasma). Twelve phenolics were determined with HPLC. Strawberries had no effect on the antioxidant activity of native plasma and circulating phenolics. Non-urate plasma DPPH decomposition increased from 5.7 ± 0.6% to 6.6 ± 0.6%, 6.5 ± 1.0% and 6.3 ± 1.4% after 3, 6 and 9 days of supplementation, respectively. The wash-out period reversed this activity back to 5.7 ± 0.8% (p<0.01). Control subjects did not reveal any changes of plasma antioxidant activity. Significant increase in urinary urolithin A and 4-hydroxyhippuric (by 8.7- and 5.9-times after 6 days of supplementation with fruits) was noted. Strawberry consumption can increase the non-urate plasma antioxidant activity which, in turn, may decrease the risk of systemic oxidants overactivity.
Determination of the optimum harvest window plays a key role in the agro-food chain as the quality of fruit depends on the right harvesting time and appropriate storage conditions during the postharvest period. Usually, indices based on destructive measurements are used for this purpose, like the De Jager Index (PFW-1), FARS index and the most popular Streif Index. In this study, we proposed a biospeckle method for the evaluation of the optimum harvest window (OHW) of the “Ligol” and “Szampion” apple cultivars. The experiment involved eight different maturity stages, of which four were followed by long cold storage and shelf life to assist the determination of the optimum harvest window. The biospeckle activity was studied in relation to standard quality attributes (firmness, acidity, starch, soluble solids content, Streif Index) and physiological parameters (respiration and ethylene emission) of both apple cultivars. Changes of biospeckle activity (BA) over time showed moderate relationships with biochemical changes during apple maturation and ripening. The harvest date suggested by the Streif Index and postharvest quality indicators matched with characteristic decrease in BA. The ability of biospeckle method to characterize the biological state of apples was confirmed by significant correlations of BA with firmness, starch index, total soluble solids and Streif Index, as well as good match with changes in carbon dioxide and ethylene emission. However, it should be noted that correlations between variables changing over time are not as meaningful as independent observations. Also, it is a well-known property of the Pearson’s correlation that its value is highly susceptible to outlier data. Due to its non-selective nature the BA reflected only the current biological state of the fruit and could be affected by many other factors. The investigations showed that the optimum harvest window for apples was indicated by the characteristic drop of BA during pre-harvest development. Despite this, at the current state of development the BA method cannot be used as an indicator alone. Due to rather poor results for prediction in OHW the BA measurements should be supported by other destructive methods to compensate its low selectivity.
In this study, the biospeckle technique was evaluated for monitoring of apple bull’s eye rot development and product quality in general, during storage under various conditions and during subsequent shelf life. This non-destructive optical method is based on the analysis of laser light variations scattered from the sample. Apples of the cultivars ‘Pinova’ and ‘Topaz’, susceptible to bull’s eye rot, were used in two independent experiments. In the first, apples were non-destructively monitored for five months during cold storage. After that time, 34% of ‘Pinova’ and 21% of ‘Topaz’ apples displayed visible surface lesions. The increase of biospeckle activity was observed during the development of fungal disease. In the second experiment various storage conditions were used and apples were tested during their shelf life by non-destructive and destructive methods. This study showed that biospeckle activity decreased during shelf life, irrespective of storage conditions.
Edible coatings are an innovative solution for food producers and suppliers looking for healthy alternatives that would be appealing to consumers seeking for ready-made products in fresh form. Low-processed horticulture products are expected to appear in more and more convenient form, ready to eat and completely safe. The application of edible surface films contributes to the extension of shelf life while maintaining strict hygiene standards. Properly selected coating components are not only able to slow down the decomposition processes but also inhibit microbial growth, thus preventing quality losses and eliminating any potential threats to health. The additional use of modified atmosphere packaging (MAP) can significantly increase the shelf life of fruit and vegetables both fresh and minimally processed. However, single treatments (edible coatings and MAP) are limited in maintaining the quality and shelf life of fresh and fresh-cut fruit and vegetables. Little is known about the synergistic effect of MAP and edible coatings, and more research is necessary. The synergic action means combined action—first applying the edible coating, then packing in MAP.