The aim of this study was to assess the performance and stability of betacyanin compounds present in enriched extracts of red-fleshed pitaya peels (Hylocereus costaricensis) and the flowers of Amaranthus caudatus; they were evaluated as natural food colorants in tagliatelle pasta and meringue cookies. The recovered natural extracts showed promising stability, maintaining a deep pink color over a storage time of 14 days, without deeply changing the chemical composition. A number of factors were assessed, including the microbial load, texture, color, nutritional value, and contents of organic acids, fatty acids, and even free sugars of the products. Some significant interactions between the type of colorant and storage time contributed to the changes in some analyzed parameters, as can be observed from the results for organic and fatty acids in the tagliatelle pasta and meringue cookies. Another significant achievement was the reduction in the microbial load during the storage time, which strengthens the antibacterial power of these natural extracts.
The plant kingdom is an endless source of molecules that can be applied in almost all realms of society.
The food industry has profited from the use of plants and their derived materials for many decades.
Recently, the food industry has been looking into plants to find different ways of either preserving, coloring
or sweetening foods. In this work, leaf extracts of Arbutus unedo L. obtained by dynamic maceration
and ultrasound assisted extraction with prior optimization of their extraction conditions through the
response-surface methodology, were incorporated in quark cheese as natural preservatives and analyzed
over 8 days of shelf-life. Both extracts showed antioxidant activity with no toxicity towards primary cell
lines at the maximum tested concentration, as well as antibacterial activity, especially against Gram-positive
strains. After their incorporation in quark cheese, no significant changes were observed in the nutritional
profile and physical traits of the quark cheeses, while the microbial load was highly reduced in the
cheese, especially using the extracts obtained from dynamic maceration. Thus, leaf extracts of A. unedo
can be promising candidates for use in the food industry as natural preservatives.
This work proposes the application of astaxanthin-rich H. pluvialis wet paste (HPW) as a partial substitute for wheat flour in the preparation of filloas, a dish that combines the basic ingredients of industrial bakery. The nutritional and color profile of HPW-enriched samples was evaluated by comparative analysis with a mixture of synthetic food dyes. The highest content of carotenoids (798 ± 12 µg g−1) and fatty acids (76 ± 2mgg−1) was obtained for a filloa fortified with H. pluvialis in contrast to a non-significant dye response. Subsequently, the color stability of the fortified filloa was evaluated over time (3, 6 and 9 days), as well as its physicochemical properties and microbiological profile. As a result, HPW provided filloas with a longer shelf life, brightness (*L), and texture, in comparison with a mixture of synthetic dyes. In addition, an inhibitory effect of HPW towards mesophilic aerobic microorganisms in the food was obtained.
