Innovative minimal processing of mini broccoli for keeping quality and safety and enhancing bioactive compounds

[ENG] Broccoli has been described as the ‘super–vegetable’ in the media after a great number of epidemiological and laboratory studies on this Brassica specie. These studies have shown numerous health–promoting properties of broccoli such as chemopreventive, antioxidant, antitumor, antimutagenicity, anti–inflammatory, antimicrobial, antiviral and reduction of coronary heart disease risk. These properties are related to the high content of broccoli in phenolic compounds, glucosinolates (isothiocyanates –ITC–), carotenoids, vitamins, fatty acids, minerals, etc. For these reasons, the broccoli consumption has been promoted, unless the Spanish consumers are still reluctant to this vegetable due to its slightly bitter and astringent flavour and sulphur aromas (when cooked). In order to promote its consumption, the breeding companies have developed natural broccoli hybrids with other Brassica species with milder flavour than conventional varieties, such as the kailan or Chinese broccoli. This new kailan–hybrid broccoli is a vegetable with remarkable more pleasant flavour and aroma than the conventional broccoli varieties, and with a bioactive and nutritive profile similar to that of broccoli and kailan. Kailan–hybrid broccoli assembles the requirements for an excellent vegetable for the minimal processing or fresh–cut (FC) and fifth range product industries. However, the processing and storage of FC and fifth range commodities imply important changes on the physicochemical, microbial, sensory, bioactive and nutritional quality of them. Furthermore, the association of foodborne outbreaks with these products has considerably increased during the last years. In this way, and due to the undesirable by–products derived of the commonly used NaClO as sanitizer agent by the FC and fifth range industry, it is imperative to optimise the emerging NaClO–alternative sanitising treatments for the kailan–hybrid broccoli. Among them, the electrolysed water (EW), ultraviolet C light (UV–C) and the superatmospheric oxygen packaging (HO) have been studied. This Ph. D. Thesis covers many of the above mentioned research needs. In addition, the real health benefits of the consumption of this kailan–hybrid broccoli (raw or cooked) have been studied in vivo, obtaining a complete scientific–technologic knowledge of this particular vegetable from farm to human cells. The research works have been performed within the Postharvest and Refrigeration Group and the Food Quality and Health Department of the Institute of Plant Biotechnology of the Universidad Politécnica de Cartagena (UPCT, Cartagena, Spain). Some equipment of the Centro Tecnológico Nacional de la Conserva y la Alimentación (Molina de Segura, Murcia, Spain) and the Centro de Cualificación Turística (Murcia, Spain) have been also used in the experiments. The volunteer’s recruitment and sampling for the in vivo studies were accomplished in the Nutrition Department of the Hospital General Universitario Reina Sofía (Murcia, Spain).Universidad Politécnica de Cartagen

Microbial control in fresh horticultural products using active paper sheets with essential oils. A case study in lemon cv. Verna

Active packaging with essential oils (EOs) encapsulated in β-cyclodextrins is a strategy to achieve a controlled EOs release, whose antimicrobial and antioxidant properties are widely known. The microbial loads of lemons (cv. Verna) packaged in a box including an active paper sheet (EOs encapsulated in β-cyclodextrins) was studied during refrigerated storage (8 ºC) with supplementary commercialization periods (5 days at room temperature). Lemons preserved with active sheets showed 0.5 and ≈3 log CFU cm -2 lower mesophilic loads than control samples after 5 weeks of refrigeration and their respective commercialization periods. In addition, the active sheets reduced Enterobacteriaceae and yeasts/molds growth by ≈1, 1.23, and 0.1 log CFU cm -2, respectively. On the other side, the physicochemical quality (soluble solid content, pH and titratable acidity) of lemons was not affected by the active packaging. In conclusion, the active packaging preserved the microbial quality in lemon while physicochemical quality was not affected

Effect of active paper sheets with encapsulated essential oils on lemon quality during its refrigerated conservation

Essential oils (EOs) are highly appreciated plant products in the food industry as sustainable alternative preservatives due to their high antimicrobial activity. For this reason, active packaging with EOs is a strategy with high potential for the preservation of fresh fruit and vegetables. In this work, the evolution of the physicochemical quality of lemons (var. Verna) in boxes with active paper sheets (EOs encapsulated in β-cyclodextrins) was studied for 5 weeks at 8 ºC, with supplementary commercialization simulation periods (5 days at room temperature). Lemons with active packaging showed less weight loss (1.3 %) compared to control samples (2.1 %), and maintained 30 % more firmness after 5 weeks, while color was not affected (p >0.05). In conclusion, the packaging of lemons with active paper sheets can be considered as an excellent conservation alternative, since it releases EO in a controlled manner preserving the lemon quality during both refrigerated and commercialization periods

Effect of stevia supplementation of kale juice spheres on their quality changes during refrigerated shelf life

Kale is a vegetable with high contents of health–promoting compounds although its consumption as a beverage is highly limited due to its bitter flavour. Nonetheless, the bitter flavour of Brassicas may be masked by sweetening. Then, the effects of different stevia extracts (CTRL, S0.5 (g L–1), S1.25 and S2.5), added to an innovative kale beverage presentation, were studied on the kale juice spheres quality during 7 days at 5ºC. Kale juice spheres were produced with a double spherification technique, which allowed to obtain hydrogel spheres with high mechanical resistance.The authors express their gratitude to CNPq (Council for Scientific and Technological Development, Brazil) for a doctoral grant (232758/2014−0) made to Tâmmila Venzke Klug. The authorsare grateful to S.G. Hasa for her skillful technical assistance. The authors are also grateful to Sakata Seeds Ibérica SLU and to Sacoje SCL for providing the plant material

Influence of fruits and vegetables active packaging on refrigeration systems efficiency

The proper design of the container for fresh fruits and vegetables is very important for the correct and rapid cooling of these packaged foods. Both the bulk packaging and the primary packaging must have adequate openings, such as macro-perforations in the film that closes the primary packaging or ventilation windows as in the case of bulk packaging crates (whether cardboard or plastic). Consequently, the heat transfer coefficient will be increased, and a significant reduction in cooling time can be achieved, thus reducing the specific energy consumption (in kWh/kg of produce) in the refrigeration installation during the pre-cooling process, and during storage and transport at marketing temperature. On the other hand, the active packaging of fresh fruits and vegetables can achieve a significant decrease in respiratory activity and, therefore, a reduction in the heat produced (in kWh/kg of produce) by respiration during pre-cooling, cold storage and refrigerated transport.The authors are grateful for the grant PID2020-119882RB-I00 funded by MCIN/AEI/ 10.13039/501100011033

Fresh-Cut Fruit and Vegetables: Emerging Eco-friendly Techniques for Sanitation and Preserving Safety

The current high demand of minimally processed or fresh-cut fruit and vegetables results from the consumer’s desire for healthy, convenient, fresh, and ready-to-eat plant food-derived commodities. Fresh-cut fruits and vegetables are usually packaged under active- or passive-modified atmosphere packaging, while its shelf life must be under refrigerated conditions. The most important goal to preserve quality and safety focuses on releasing the microbial spoilage flora, since every unit operation involved will influence the final load. Sanitation in the washing step is the only unit operation able to reduce microbial load throughout the production chain. Chlorine is widely used as an efficient sanitation agent, but some disadvantages force to find eco-friendly emerging alternatives. It is necessary to deal with aspects related to sustainability because it could positively contribute to the net carbon balance besides reducing its use. Several innovative techniques seem to reach that target. However, industrial changes for replacing conventional techniques request a fine knowledge of the benefits and restrictions as well as a practical outlook. This chapter reviews the principles of emerging eco-friendly techniques for preserving quality and safety of fresh-cut products in order to meet the expected market’s demand

Abiotic stress combination to improve healthiness of fresh vegetables smoothies

Several epidemiological studies have revealed the potential benefits of an appropriate and equilibrated diet rich in fruit and vegetables to prevent several diseases in those people with genetic predisposition. Phytochemicals of vegetables, such as phenolic compounds, carotenoids and vitamins offer health-promoting benefits. Orange vegetables, such as carrots, pumpkin, sweet potatoes, etc., are very popular in the Mediterranean diet. These vegetables are important contributors of antioxidants in the diet as polyphenols, carotenoids and vitamins (A, C, E, etc). Accordingly, these vegetables could be used as a functional food if the content of such phytochemicals is enhanced. Abiotic stresses, such as UV-C, superatmospheric oxygen, wounding, etc., applied during postharvest can be used as a tool to enhance phytochemicals. Hence, these stressed vegetables with high health-promoting properties can be consumed as a functional food, with high added value, or as a natural nutraceutical to be included in other functional foods like beverages like smoothies.We acknowledge Spanish Ministry of Economy and competitiveness MINECO (AGL2013-48830-C2-1-R) and FEDER for financial support

Effect of essential oil vapors on the shelf life of packaged fresh sliced mushrooms

[SPA] El champiñón (Agaricus bisporus) laminado, envasado y conservado en refrigeración, tiene una vida útil corta que puede verse reducida debido al pardeamiento. La oxidación de los tejidos y pardeamiento puede verse reducida mediante el tratamiento con aceites esenciales (AEs), incluso a bajas concentraciones. En este trabajo se ha estudiado el efecto de la aplicación de vapores de AEs en la conservación del champiñón fresco laminado. El champiñón laminado tratado con vapores de AEs presentó mejor control de la microbiología alterante (principalmente de Pseudomonas spp. con 1,7 unidades logarítmicas menos), menor pardeamiento y mayor firmeza (30% superior) durante la vida útil. El producto tratado con AEs fue muy apreciado por los panelistas, que no detectaron una alteración significativa del sabor debido a los AEs. [ENG] The packaged fresh sliced mushroom (Agaricus bisporus) stored in refrigeration has a short shelf life that can be reduced due to browning. Tissue oxidation and browning can be reduced through essential oils (EOs) treatment, even at low concentrations. In this work, the effect of essential oils vapors treatment on fresh sliced mushroom preservation has been studied. The sliced mushroom treated with EOs vapors showed better control of the spoilage microbiology, mainly of Pseudomonas spp. (approximately 1.7 log unit lower), less browning, greater firmness (30% higher) during the shelf life and a good sensory evaluation by the panelists. The product treated with EOs was highly appreciated by the panelists, without detecting significant alteration of the taste due to the EOs.Se agradece a la empresa Champinter por ceder las muestras para este experimento. La alumna Alejandra Navarro también agradece al Grupo de Ingeniería del Frío y de la Seguridad Alimentaria por la beca predoctoral de la que disfruta

Inhibition of ethylene production in broccoli by essential oil vapors released from active packaging

[SPA] El brócoli es una inflorescencia cuya vida útil puede verse altamente reducida durante su conservación postcosecha debido a la alta sensibilidad de esta Brassica al etileno. El efecto visual más evidente debido al etileno es el amarilleamiento de esta hortaliza. La producción de etileno del brócoli podría ser reducida con aceites esenciales (AEs), incluso a bajas concentraciones. En esta Tesis se estudiará el efecto de aceites esenciales (complejos de inclusión formados con β-ciclodextrina) liberados de un envase activo sobre la producción de etileno del brócoli. Los resultados esperados son: un descenso en la producción de etileno (y conocimiento de la expresión génica de las enzimas claves en la ruta de biosíntesis del etileno) y un aumento de la vida útil del brócoli con el envase activo con aceites esenciales. [ENG] Broccoli is an inflorescence whose useful life can be highly reduced during its post-harvest storage due to the high sensitivity of this Brassica to ethylene. The most obvious visual effect due to ethylene is the yellowing of this vegetable. The ethylene production in broccoli could be reduced with essential oils (EOs), even at low concentrations. In this Thesis, the effect of encapsulated essential oils (inclusion complexes formed with β-cyclodextrin) released from an active package will be studied on the ethylene production of broccoli. The expected results are: decrease of the ethylene production (understanding the gene expression of the key enzymes of the ethylene biosynthesis pathway) and extension of the broccoli shelf life with the active packaging with EOs

Addition of encapsulated evoo in the breadcrumbs improves food safety and shelf life of refrigerated map packaged chicken nuggets

Consumer’s health awareness increasement towards convenience foods is compromising refrigerated pre-fried breaded products demand. Thus, this study aimed to obtain chicken nuggets incorporating encapsulated extra-virgin olive oil (EVOO) (as α-cyclodextrin complex) during the breading phase (mixing breadcrumbs and complex in a ratio of 2:1 w/w) to obtain a product by infrared baking (new technology, NT) with similar, or even higher, quality than deep pre-fried ones (CTRL). Evaluation of the obtained products (MAP packaged under 30 % CO2 / 70 % /N2) stored at 4 ºC was conducted for up to 14 days. NT samples maintained their fresh appearance throughout conservation and showed (p > 0.05) similar color values of pre-fried nuggets. Fat levels were reduced by 84.5 %, and sensory scores showed similar results as CTRL samples. Furthermore, NT nuggets reduced microbial growth, extending refrigerated shelf life from 2 to 4 weeks. In conclusion, encapsulated EVOO in the breading phase combined with infrared baking allowed to obtain healthier, higher quality nuggets with longer shelf life.This research has received funding from the Centre for the Development of Industrial Technology (CDTI, Madrid, Spain) through the project “New process technologies for healthy breaded products (Ref. IDI- 20190627)”