Guava (Psidium guajava L.), is a fruit considered native to the American tropics. It is of great economic importance in many countries of the world, due to its high production and diversity of products derived from its fruit. It can be consumed fresh or processed. During the fruit’s processing, some residues are generated, such as seeds, rinds, and pulp, which is about 30% of the fresh fruit’s volume. Different studies have shown that it can be used in various industries, such as food, chemical, and pharmaceutical. By-products or processing residues have valuable components. Evidence indicates that it contains significant amounts of dietary fiber (soluble and insoluble), vitamins (A, B, C, β-carotene), essential oils, minerals, proteins (transferrin, ceruloplasmin, albumin), pectins, antioxidants (flavonoids, flavonols, condensed tannins) and volatile organic compounds; these elements can help in the prevention of chronic and degenerative diseases. P. guajava L. is considered a nutraceutical due to its compounds with beneficial properties on health and disease prevention. Therefore, this paper aims to review the physicochemical composition of the different by-products of the processing of guava and its reported uses.

Agroindustrial activities generate various residues or byproducts which are inefficiently utilized, impacting the environment and increasing production costs. These byproducts contain significant amounts of bioactive compounds, including dietary fiber with associated phenolic compounds, known as antioxidant dietary fiber (ADF). Phenolic compounds are related to the prevention of diseases related to oxidative stress, such as neurodegenerative and cardiovascular diseases. The mechanism of ADF depends on its chemical structure and the interactions between the dietary fiber and associated phenolic compounds. This work describes ADF, the main byproducts considered sources of ADF, its mechanisms of action, and its potential use in the formulation of foods destined for human consumption. ADF responds to the demand for low-cost, functional ingredients with great health benefits. A higher intake of antioxidant dietary fiber contributes to reducing the risk of diseases such as type II diabetes, colon cancer, obesity, and kidney stones, and has bile-acid retention–excretion, gastrointestinal laxative, hypoglycemic, hypocholesterolemic, prebiotic, and cardioprotective effects. ADF is a functional, sustainable, and profitable ingredient with different applications in agroindustry; its use can improve the technofunctional and nutritional properties of food, helping to close the cycle following the premise of the circular economy.

Background:The fermentation substrate efficiency of glucose supplemented with guava seed flour (GGSF) or glucose supplemented with dry Aspergillus niger mycelium (GANM) was evaluated during the production of biomass and antimicrobial compounds by the lactic acid bacteria Weissella confusa. Results: The fermentation substrate efficiency was measured by comparing the biomass formation, substrate consumption, substrate conversion, antimicrobial activity and product yield. The antimicrobial activity was measured against a commercial Staphylococcus aureus strain. The results were compared against fermentations performed in a commercial substrate (CS), the MRS (Man-Rogosa-Sharpe) substrate. The fermentations were performed discontinuously for 4 hrs at 100 rpm and 32ºC. The biomass production exhibited a statistically significant difference (P ≤ 0.05) between treatments. The biomass production was 13.98% higher in the CS than in the GGSF and GANM substrates; however, there were no statistically significant differences for the specific growth rate. Conclusions: The GGSF and GANM substrates favored an antimicrobial activity against Staphylococcus aureus during the second and third hours of fermentation (inhibition diameter was 6.11% and 4.72%, respectively). The GGSF, GANM and CS substrates did not present statistically significant differences for the production of antimicrobial substances against Staphylococcus aureus. Therefore, GGSF and GANM can be considered as viable and economical alternative nitrogen sources for the production of the antimicrobial compounds formed by Weissella confusa in submerged fermentations.

Se evaluaron barras de cereal, como matriz sólida, para la incorporación de un microorganismo probiótico. Se midió la aceptabilidad, perfil de sabor, perfil de textura y el aporte nutricional durante el proceso de elaboración de la barra de cereal. Se utilizó la bacteria ácido láctica Weissella confusa. La aceptabilidad del producto en cuanto a sabor, color, olor y textura fue superior al 50%. El perfil de sabor indicó que los sabores a arroz soplado, dulce y uvas pasas fueron más acentuados, y no se percibió sabor a rancio. Las formulaciones mostraron carácter prebiótico (5.91% en base seca de fibra dietaria). La bacteria probiótica disminuyó su viabilidad de 3.73x10 11 a 5.62x10 7 UFC/g. Sin embargo, el recuento se encontró dentro del rango para ser considerado producto probiótico. Los resultados demostraron que la barra de cereal puede emplearse como matriz sólida para el desarrollo de formulaciones sinérgicas probióticas y prebióticas.

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