Optimization of microwave-assisted extraction of ergosterol from Agaricus bisporus L. by-products using response surface methodology

This work intends to valorise by-products of the industrial processing of mushrooms to obtain ergosterol as a value-added compound. Agaricus bisporus L. is the world’s most consumed mushroom and one of the richest sources of ergosterol. Microwave-assisted extraction was used to replace conventional techniques that are time-consuming and need large amounts of solvent. Time (3-20 min), temperature (60-210 ºC) and solid-liquid ratio (1-20 g/L) were found the relevant variables to analyze the extraction process. To maximize the ergosterol extraction yield, response surface methodology was used to optimize the process. The global optimal extraction conditions were determined and comprise: 19.4±2.9 min, 132.8±12.4 ºC and 1.6±0.5 g/L, yielding 556.1±26.2 mg of ergosterol per 100 g of mushroom by-products. In the MAE optimal conditions, it was possible to obtain ergosterol in a similar value to the one obtained in other works when using the Soxhlet extraction method with a significant decrease in the time of extraction. The results show the potential of using the by-products of an agroindustry, mushrooms processing industry, as productive sources of ergosterol.The authors acknowledge FCT (Portugal) for financial support to CIMO (PEst-OE/AGUI/0690/2014), Sandrina A. Heleno (SFRH/BPD/101413/2014) and L. Barros (SFRH/BPD/107855/2015), to FCT/MEC and FEDER under Programme PT2020 for financial support to LSRE (Project UID/EQU/50020/2013), and to QREN, ON2 and FEDER (Projects NORTE-07-0124-FEDER-000014 and NORTE-07-0162-FEDER-000050). The authors also acknowledge Xunta de Galicia for financial support of the post-doctoral researcher M.A. Prieto, and to Patrícia Diz for some support in MAE experiments

Cytotoxic effects of hydro-ethanolic extracts from Coleostephus myconis (L.) rchb.f. flowers and green parts

The species Coleostephus myconis (L.) Rchb.f. is considered as being a harmful and persistent weed, with constant presence in abandoned farmland. Prevailing in the Portuguese flora, C. myconis belongs to the Asteraceae family, which is recognized for its global medicinal value and high antioxidant power, as described in different research works. Nevertheless, before considering incorporating this species in food of pharmaceutical applications, it is imperative to evaluate their potential toxicity.N/

Long-term storage effect on chemical composition, nutritional value and quality of Greek onion landrace "vatikiotiko"

The effect of storage at two temperatures (5 ± 1 and 25 ± 1 °C and 60-70 ± 5% RH for both temperatures) on marketability and quality features of dry bulbs of local landrace "Vatikiotiko", "Sivan F1", "Red Cross F1" and "Creamgold" was examined. During storage measurements for fresh and dry weight of bulbs, tunic and flesh color, bulb firmness, nutritional value and mineral composition were taken at regular intervals. Storage concluded when either bulbs lost marketable quality or sprouting occurred. "Vatikiotiko" onion can be stored for at least 7 months at 25 ± 1 °C, whereas at 5 ± 1 °C storage could be prolonged without significant marketability and quality loss. The fact that "Vatikiotiko" landrace can be considered a "storage" onion has to be capitalized in order to increase total production and yield, since storage could cover the market needs that arise throughout the year. © 2016 Published by Elsevier Ltd

Effect of storage on quality features of local onion landrace 'Vatikiotiko'

'Vatikiotiko' is a Greek landrace of Allium cepa L. of the Liliaceae family, cultivated only in the region of Vatika, in Lakonia prefecture as a short day onion. The dry bulbs are a quality product highly sought after in Greek market, since this is the earliest onion that comes out during Spring. However, so far the production is limited and the potential of this landrace is not fully developed. In the present study we examined the effect of storage at two temperatures (23±1 and 5±1°C) and 60-70% RH (relative humidity) on marketability and quality features of dry bulbs of 'Vatikiotiko' landrace and 'Sivan F1' which is also cultivated in the specific region. The experiments were carried out at the University of Thessaly, Greece during the period 2014-2015. The quality features that were recorded during storage included fresh weight loss, bulb firmness, antioxidants and sugar's composition. The measurements were taken at regular intervals and the storage was completed when either bulbs had not marketable quality or sprouting occurred. So far the results have shown that 'Vatikiotiko' onion can be stored for 7 months at both temperatures, whereas at 5±1°C storage could be prolonged for almost 8 months without significant marketability and quality loss. Similarly, 'Sivan F1' sprouting occurred after 5 and 6 months at 23±1 and 5±1°C, respectively. Therefore, the fact that 'Vatikiotiko' landrace is a storage onion allows for further valorization in order to increase total production and yield, since the stored product could cover the market needs that arise throughout the year, whereas breeding is needed in order to minimize the genetic variability of the landrace and increase uniformity of the final product

Biostimulants application alleviates water stress effects on yield and chemical composition of greenhouse green bean (phaseolus vulgaris l.)

The increasing scarcity of water demands proper water management practices to ensure crop sustainability. In this study, the effect of drought stress and biostimulants application on the yield and chemical composition of green pods and seeds of common bean (Phaseolus vulgaris L.) was evaluated. For this purpose, four commercially available biostimulant products, namely Nomoren (G), EKOprop (EK), Veramin Ca (V), and Twin-Antistress (TW), were tested under two irrigation regimes: normal irrigation (W+) and water-holding (W-) conditions. The highest increase (20.8%) of pods total yield was observed in EKW+ treatment due to the formation of more pods of bigger size compared to control treatment (CW+). In addition, the highest yield under drought stress conditions was recorded for the GW- treatment (5691±139 kg/ha). Regarding the effects of biostimulants on the protein and ash content of pods, the application of VW+ treatment (first harvest of pods; 201±1 and 79±1 g/kg dw for proteins and ash content, respectively) and GW+ (second harvest of pods; 207.1±0.1 and 68.4±0.5 g/kg dw for proteins and ash content, respectively) showed the best results. For seeds, the application of GW+ treatment resulted in the highest content for fat, protein, and ash content (52.7±0.1, 337±1, 56±1 g/kg dw) and energetic value (5474±3 kcal/kg dw). γ-tocopherol was the main detected tocopherol in pods and seeds, and it was significantly increased by the application of TWW- (first harvest of pods; 6410±40 μg/kg dw), VW- (second harvest of pods; 3500±20 μg/kg dw), and VW+ (seeds; 39.8±0.1 g/kg dw) treatments. EKWtreatment resulted in the lowest oxalic acid content for both pod harvests (26.3±0.1 g/kg dw and 22.7±0.2 g/kg dw for the first and second harvest of pods, respectively) when compared with the rest of the treatments where biostimulants were applied, although in all the cases, the oxalic acid content was considerably low. Fructose and sucrose were the main sugars detected in pods and seeds, respectively, while the highest content was recorded for the TWW- (first harvest of pods) and GW- (second harvest of pods and seeds) treatments. The main detected fatty acids in pods and seeds were α-linolenic, linoleic, and palmitic acid, with a variable effect of the tested treatments being observed. In conclusion, the application of biostimulants could be considered as an eco-friendly and sustainable means to increase the pod yield and the quality of common bean green pods and seeds under normal irrigation conditions. Promising results were also recorded regarding the alleviation of negative effects of drought stress, especially for the application of arbuscular mycorrhizal fungi (AMF; G treatment), which increased the total yield of green pods. Moreover, the nutritional value and chemical composition of pods and seeds was positively affected by biostimulants application, although a product specific effect was recorded depending on the irrigation regime and harvesting time (pods and seeds). © 2020 by the authors

Chemical characterization of the medicinal mushroom Phellinus linteus (Berkeley & Curtis) Teng and contribution of different fractions to its bioactivity

Mushrooms are widely appreciated for their organoleptic qualities, being also recognized as good sources of bioactive compounds that provide antioxidant, antimicrobial and cytotoxic activities. Polysaccharides (including glucans) are often pointed out as the most bioactive compounds isolated from mushrooms, but other molecules such as triterpenoids, might also be highlighted for their bioactivity. In scientific research, when isolated compounds are used, potential synergistic effects might be lost. Accordingly, the bioactivity of Phellinus linteus was evaluated in selected fractions (polysaccharides, glucans and triterpenoids), as well as in the methanolic and ethanolic extracts. The best antioxidant and antibacterial activities were obtained with methanolic extract, while glucan and triterpenoid fractions gave the strongest antifungal activity. In contrast, ethanolic extract gave the best results in cytotoxic activity, indicating that the bioactive compounds present might act synergistically. The differentiated activity of P. linteus fractions and extracts could be useful to find antimicrobial, antioxidant and cytotoxic agents as alternatives to synthetic chemicals with application in agriculture, food industry or pharmacy

Potato biodiversity: A linear discriminant analysis on the nutritional and physicochemical composition of fifty genotypes

Fifty potato genotypes from twenty-four different countries of origin, four different flesh colours (yellow, purple, red and marble) and different cultivation types (Andean accessions, landraces, breeder lines and cultivated varieties) were studied in terms of their nutritional and physicochemical characteristics. In general, cultivated varieties and breeder lines showed the highest similarity (slight differences only in some particular fatty acids distributions: C10:0, C12:0 and C22:0) concerning the physicochemical parameters assayed in this work, independently of the geographical origin or tuber flesh colour of these genotypes. Nonetheless, some of the studied landraces and Andean accessions proved to be similar enough to be considered as genotypes with good potential for commercial cultivation. These results can contribute to the supply of new potato genotypes into sustainable farming systems, supporting the protection of potato biodiversity, particularly Andean accessions, landraces and coloured genotypes (red or purple flesh) which are not widely cultivated so far. © 2020 Elsevier Lt