Quality and Safety of Ready-to-Eat Golden Thistle (Scolymus hispanicus L.): A New Product for Traditional Italian Dishes.

Golden thistle (Scolymus hispanicus L.) is a wild edible plant belonging to Asteraceae family, with a great potential for food applications. The aim of this study was to identify the best cooking procedure able to provide a high-quality, ready-to-use product. For this purpose, leaf midribs (the most used edible part of the plant) were cooked by boiling, steaming, and 'sous vide', and the cooked products were compared for their phenolic content and composition, antioxidant activity, sugar and inorganic ion content, organoleptic characteristics, and microbial safety, this latter also during storage. In general, boiling caused a decrease in the value of these parameters, despite being the best product for taste and overall acceptability. On the contrary, steaming and 'sous vide' resulted in the best treatments to preserve antioxidant activity, total phenols, and chlorogenic acid. In particular, in 'sous vide' cooked samples, a significant increase in the value of these parameters and a remarkable decrease in nitrate content were found. Moreover, 'sous vide' resulted in the best treatment also regarding microbial safety during shelf life; actually, after 15 days of storage at 8 °C, Enterobacteriaceae and mesophilic aerobic bacteria were not detectable in 'sous vide' samples. These results contributed to increase the knowledge of a wild edible plant with high nutritional properties and promoting its consumption by obtaining a ready-to-use product with good organoleptic characteristics and endowed with a long period of shelf life.

Bioactive Phenolics and Antioxidant Capacity of Some Wild Edible Greens as Affected by Different Cooking Treatments.

The study aimed to assess the influence of three cooking methods (boiling, steaming, and microwave-cooking) on (i) composition in individual phenolic compounds, (ii) total phenolic content (TPC), and (iii) total antioxidant activity (TAA) of eight Mediterranean wild edible species (Asparagus acutifolius, Asphodeline lutea, Beta vulgaris, Helminthotheca echioides, Sonchus oleraceus, Taraxacum officinale, Urospermum picroides, Urtica dioica). In raw greens, several caffeic acid derivatives (chicoric, caftaric, chlorogenic, neochlorogenic, 1,5-and 3,5-dicaffeoylquinic acids) and flavonoids (glycosides of apigenin, luteolin, quercetin, isorhamnetin, kaempferol) were identified. Cooking treatments did not affect qualitative phenolic composition, while quantitative changes were recorded in some phenolic compounds and in TPC. Generally, boiling decreased TPC and TAA, while chicoric, caftaric, chlorogenic acids and quercetin-3-rutinoside increased in some species after steaming and microwave-cooking, showing positive correlation with TAA. Results confirmed steaming and microwave-cooking as mild procedures able to increase antioxidant capacity of some species, producing beneficial effects on their nutraceutical properties.

Degradation of Aflatoxin B1 by a Sustainable Enzymatic Extract from Spent Mushroom Substrate of Pleurotus eryngii.

Ligninolytic enzymes from white-rot fungi, such as laccase (Lac) and Mn-peroxidase (MnP), are able to degrade aflatoxin B1 (AFB1), the most harmful among the known mycotoxins. The high cost of purification of these enzymes has limited their implementation into practical technologies. Every year, tons of spent mushroom substrate (SMS) are produced as a by-product of edible mushroom cultivation, such as Pleurotus spp., and disposed at a cost for farmers. SMS may still bea source of ligninolytic enzymes useful for AFB1 degradation. The in vitro AFB1-degradative activity of an SMS crude extract (SMSE) was investigated. Results show that: (1) in SMSE, high Lac activity (4 U g-1dry matter) and low MnP activity (0.4 U g-1dry matter) were present; (2) after 1 d of incubation at 25 °C, the SMSE was able to degrade more than 50% of AFB1, whereas after 3 and 7 d of incubation, the percentage of degradation reached the values of 75% and 90%, respectively; (3) with increasing pH values, the degradation percentage increased, reaching 90% after 3 d at pH 8. Based on these results, SMS proved to be a suitable source of AFB1 degrading enzymes and the use of SMSE to detoxify AFB1 contaminated commodities appears conceivable.

Purification, biochemical characterization and cloning of a new cationic peroxidase isoenzyme from artichoke.

A cationic soluble peroxidase isoenzyme (CysPrx) has been purified and characterized from artichoke (Cynara cardunculus subsp. scolymus (L.) Hegi) leaves by combination of aqueous two phase extraction, ion exchange chromatography, and gel filtration. The purification fold was 149 and the activity recovery 5.5%. CysPrx was stable from 5 to 45 °C with a pH optimum around 5.5; the pI was 8.3 and the MW of 37.7 ± 1.5 kDa. MALDI-TOF MS analysis provided partial peptide sequences and resolved CysPrx isoenzyme into two putative isoforms. The presence of these isoforms was confirmed by the isolation of full-length cDNA encoding CysPrx that generate two slightly different sequences coding for two putative CysPrx: CysPrx1 and CysPrx2. The obtained MS peptides showed a 35% coverage with 100% identity with the two CysPrx deduced protein sequences. A molecular modeling analysis was carried out to predict in silico the protein structure and compare it with other plant Prx structures. Considering that CysPrx is quite stable, the study carried out in this paper will offer new insights for the production of the recombinant protein for utilization of CysPrx as an alternative Prx for food technology, biomedical analysis and bioremediation.