Effect of high hydrostatic pressure on the quality of four edible flowers: Viola × wittrockiana, Centaurea cyanus, Borago officinalis and Camellia japonica

Casal

Food sci. technol. int.

et al. 2019

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Edible flowers, such as pansies, have a short shelf-life. Crystallization is a treatment used to prolong the shelf-life of fruits and vegetables. So, the aim of the present work was to investigate the effect of crystallization in the physicochemical, microbial and antioxidant properties of pansies ( Viola×wittrockiana) during room temperature storage (7, 15, 30, 60 and 90 days). Comparing fresh and crystallized pansies, significant differences were detected. After 90 days of storage, crystallized pansies kept similar appearance to those immediately after treatment. A significant decrease in water activity, moisture, ash and protein contents was observed between 0 and 90 days of storage for crystallized pansies. Some bioactive compounds, such as flavonoids and monomeric anthocyanins, showed a significant decrease after 90 days of storage, while hydrolysable tannins increased. Concerning phenolic compounds, these maintained constant along storage. The microbial load of crystallized pansies during all storage time was lower than fresh ones. So, crystallization can be an effective method for pansies preservation, being some nutritional and bioactive compounds, little affected during storage. However, crystallization contributed to a high increase in sugar content and energy values compared to fresh pansies.

Section: Resultsmentioning

confidence: 98%

Physicochemical, antioxidant and microbial properties of crystallized pansies (Viola × wittrockiana) during storage

Casal

Food sci. technol. int.

et al. 2019

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“…For example, borage and camellia showed an unacceptable appearance (loss of structure and firmness) after HHP application, while centaurea presented good appearance at 100/5 MPa/min; however, the shelf life did not increase. [37] On contrary, pansies submitted at 75/5 or 75/10 MPa/min maintained good appearance over 20 days of storage at 4°C, as well as HHP induced the production of bioactive compounds. This phenomenon might be associated with structural alteration of the cells provoked by the HHPs, yielding a higher amount of extracted metabolites or a physiological response of the flower to stress conditions at higher pressurization levels.…”

Section: High Hydrostatic Pressurementioning

confidence: 93%

“…This phenomenon might be associated with structural alteration of the cells provoked by the HHPs, yielding a higher amount of extracted metabolites or a physiological response of the flower to stress conditions at higher pressurization levels. [37] The effect of HHP on the retention and bioactivity of natural phytochemicals present in Echinacea purpurea, as well as the microbial load, were studied by Chen et al [38] They reported that HHP significantly reduced the microbial contamination in flowers without affecting the retention of phytochemical, such as chicoric, caftaric and chlorogenic acids, and total alkamides.…”

Section: High Hydrostatic Pressurementioning

confidence: 99%

Post-harvest technologies applied to edible flowers: A review

Saraiva

Food Reviews International

et al. 2018

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This review intends to summarize the current knowledge on the postharvest technologies applied to edible flowers, to help producers to increase their market share and to inform consumers on the technologies that are available to maintain edible flowers' quality and safety. Emerging post-harvest technologies as High Hydrostatic Pressure (HHP) or irradiation have given good results. Freeze-or vacuumdrying has shown to be highly effective in the preservation of flowers' bioactive compounds in comparison with classical drying approaches. While osmotic dehydration is already in use, the application of edible coatings and films can be a healthier alternative, without increasing solute contents.

“…In the last years, new technologies have been applied to extend the shelf‐life and maintain the quality of edible flowers, such as high hydrostatic pressure (HHP) (Fernandes, Casal, Pereira, Ramalhosa, & Saraiva, 2017a), edible coatings (Fernandes, Casal, Pereira, Pereira, et al., 2018; Fernandes, Pereira, et al., 2018), drying (Fernandes, Casal, Pereira, Saraiva, & Ramalhosa, 2018), and irradiation (Koike et al., 2015). In particular, pansies treated with HHP maintained good appearance more 14 days than untreated and induced the production of bioactive compounds (Fernandes et al., 2017a). Concerning edible coatings, pansies increased shelf‐life more 7 days than uncoated, and improved their physicochemical and microbiological quality (Fernandes, Casal, Pereira, Pereira, et al., 2018).…”

Section: Introductionmentioning

confidence: 99%

Freezing of edible flowers: Effect on microbial and antioxidant quality during storage

Casal

Journal of Food Science

et al. 2020

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Edible flowers are a new gourmet product; however, they are not always available all years. Thus, it is essential to find out technologies to guarantee this product for a longer time. Flowers of four species (borage [Borago officinalis], heartsease [Viola tricolor], kalanchoe [Kalanchoe blossfeldiana], and dandelion [Taraxacum officinale]) were subjected to freezing (in their natural form and in ice cubes) and analyzed in terms of visual appearance, the content of flavonoids, hydrolysable tannins, phenolics, antioxidant activity (2,2-diphenyl-1-picrylhydrazyl radical scavenging activity and reducing power), and microbial quality after storage for 1 and 3 months. Flowers in ice cubes showed similar appearance to fresh ones during the 3 months of storage, whereas frozen flowers were only equivalent up to 1 month with the exception of kalanchoe. Even though flowers in ice cubes showed good appearance after 3 months of storage, they had the lowest values of bioactive compounds and antioxidant activity. On the contrary, when frozen, the content of bioactive compounds maintained or even increased up to 1 month of storage compared to fresh flowers, except for borage. Furthermore, in both freezing treatments, the microorganisms' counts decreased or maintained when compared to fresh samples, except in dandelion. In general, both treatments may allow keeping the flowers after their flowering times.Practical Application: The market of edible flowers is increasing, although they are a very perishable product with short shelf-life. Edible flowers are stored in the cold (frozen or in ice cubes); however, the effect on the bioactive compounds and microbial quality that this treatment may have on borage (Borago officinalis), heartsease (Viola tricolor), kalanchoe (Kalanchoe blossfeldiana), and dandelion (Taraxacum officinale) flowers is unknown. So, the present study was conducted to increase the knowledge about the changes that freezing treatments may have in different edible flowers. The results of the present study underline that each flower has different behavior at frozen and ice cubes storage. However, freezing flowers maintain/increase the contents of bioactive compounds, while ice cubes not. Both treatments are effective in protecting flowers from microorganism growth. So, suggesting that both freezing treatments can be used as a preservative method and may allow keeping the flowers after their flowering times.