Effect of cooking and packaging conditions on quality of semi-dried green asparagus during cold storage

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.

Influence of Domestic Cooking on Quality, Nutrients and Bioactive Substances of Undaria pinnatifida

Undaria pinnatifida (UP) is a brown algae commonly consumed as food in Asian countries. The purpose of this study was to compare the effects of different domestic cooking methods (i.e., air frying (AF), microwaving, and high temperature and pressure (HTP) cooking) on the nutritional and bioactive substances in UP, as well as on UP color and texture, in order to identify methods to retain beneficial components better. In this study, microwave treatment resulted in better retention of color, polysaccharide (4.17 ± 0.07 mg glucose equivalents (GE)/g dry weight (dw) ), total phenol content (TPC) (1.50 ± 0.0062 mg gallic acid equivalents (GAE)/g dw) as well as chlorophyll a (18.18 ± 0.41 mg/g fresh weight (fw) ) and fucoxanthin (281.78 ± 17.06 μg/g dw). HTP treatment increased the TPC of UP (1.69 ± 0.0075 mg GAE/g dw), and AF treatment resulted in a lower loss of total amino acids (2.14 ± 0.15%). Overall, microwave cooking appeared to be the best among the three in producing cooked UP with high quality. This study provided a useful guideline in selection of cooking for UP which could retain more health-beneficial substances and yield products with better eating qualities to improve human diet.

Improving the bioactive ingredients and functions of asparagus from efficient to emerging processing technologies: A review

Historically, asparagus is a vegetable with abundant phytochemicals (polyphenols, saponins, asparagusic acid, and alkaloids) and crucial bioactivities (neuroprotective, antianxiety, antityrosinase, antioxidant, antibacterial, and antiasthma effects). Numerous investigations indicated that processing technologies have a significant influence on the physicochemical, functional, and microstructural characteristics of asparagus. This review presents an updated overview of novel applications of processing technologies, including ultrasound treatments (in terms of extraction, purification, and preservation), heating treatments (hydrothermal treatments, thermal treatments, and combination heating treatments), high-pressure processing, representative shelf-life extension technologies, and green extraction technologies. These physical technologies enhance the yields of bioactive substances, bioactivities and product quality. In addition, utilizing the novel technologies (ohmic heating, cold plasma, pulsed electric fields, membrane processing) and conventional technologies with novel effects to fully develop the potential of asparagus should also be taken into consideration in the future.

Nutritional and Phytochemical Composition of Mediterranean Wild Vegetables after Culinary Treatment

Studies are scarce on the nutritional and phytochemical composition of wild edible Mediterranean plants after culinary processing. This work provides the nutritional composition after culinary treatment (including dietary fiber and mineral composition) and bioactive compounds (folates, vitamin C and organic acids) of wild Rumex pulcher L., Silene vulgaris (Moench) Garcke. leaves, and wild Asparagus acutifolius L., Bryonia dioica Jacq., Humulus lupulus L., Tamus communis L. young shoots. Shoots better preserved their nutrients than leaves, due to their different tissue structure. Fresh and cooked wild greens present high dietary fiber values, and remained at remarkable levels after boiling. Na, K, Mg and Zn were lost in about 50% due to culinary processing, while Ca, Cu, Fe and Mn were more stable. Boiled leaves of S. vulgaris remained as a good Mn source. A portion of 100 g of most of the cooked analyzed species could cover a relevant percentage of the daily requirement of folates (R. pulcher and A. acutifolius providing more than 80%) and vitamin C (T. communis and A. acutifolius providing more than 35%).

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.

Application of MAP and ethylene–vinyl alcohol copolymer (EVOH) to extend the shelf-life of green and white asparagus (Asparagus officinalis L.) spears

In this study, ethylene vinyl alcohol copolymer (EVOH) and polypropylene/polyethylene (PP/PE) films combined with MAP packaging were developed to enhance the shelf-life of green and white asparagus spears. The scope of the research included measurements of weight loss, pH, acidity, color, texture, and sensory analysis as indicators of green and white asparagus spear quality for up to 17 days of storage at 2 and 10 °C. The application of modified atmosphere packaging combined with EVOH-based packaging material and refrigeration at 2 °C promoted a reduction in asparagus weight loss, preventing changes in color and texture as well as sensory quality, thereby extending the shelf-life of the asparagus. According to the obtained results, it was possible to maintain good quality of green and white asparagus for up to 17 and 10 days, respectively, when packed in MAP using EVOH-based packaging stored at 2 °C. Asparagus stored in packaging with PP/PE film showed lower quality during storage at 2 and 10 °C. These results suggest that EVOH films are potential candidates for advanced packaging materials for the asparagus packaging application.

Innovative technologies for producing and preserving intermediate moisture foods: A review

Intermediate moisture foods (IMF) or semi-dried foods (SDF) have gained more attention worldwide having features very similar to fresh food products, but with a longer shelf life. This review presents the recent developments in novel technologies and methods for the production and preservation of IMF. These include new drying methods, using agents to reduce water-activity, innovative osmotic dehydration technologies, electro-osmotic dewatering, thermal pasteurization, plasma treatments (PT), high pressure processing (HPP), modified atmosphere packaging (MAP), edible coating, active packaging (and energy efficiency, improve quality and extend the shelf life of the final food AP) and hurdle technologies (HT). Innovative methods applied to producing and preserving IMF can enhance both drying products. Yet more systematic research is still needed to bridge knowledge gaps, in particular on inactivation kinetics and mechanisms related to thermal and non-thermal pasteurization technologies for control of pathogens and spoilage micro-organisms in IMF.