Industrial biotechnology is a continuously expanding field focused on the application of microorganisms to produce chemicals using renewable sources as substrates. Currently, an increasing interest in new versatile processes, able to utilize a variety of substrates to obtain diverse products, can be observed. A robust microbial strain is critical in the creation of such processes. Lactic acid bacteria (LAB) are used to produce a wide variety of chemicals with high commercial interest. Lactic acid (LA) is the most predominant industrial product obtained from LAB fermentations, and its production is forecasted to rise as the result of the increasing demand of polylactic acid. Hence, the creation of new ways to revalorize LA production processes is of high interest and could further enhance its economic value. Therefore, this review explores some co-products of LA fermentations, derived from LAB, with special focus on bacteriocins, lipoteichoic acid, and probiotics. Finally, a multi-product process involving LA and the other compounds of interest is proposed.Fermentation 2020, 6, 23 2 of 21 by-products, were proposed to improve industrial single-product biotechnological processes [2]. One example is the use of cellulose and hemicellulose from sugarcane bagasse (a residue obtained during the bioethanol production and usually used for energy generation) for the production of value-added chemicals [3]. Likewise, glycerol, a by-product of the biodiesel industry with low value in the market, is targeted as a molecule of interest in fermentation processes. Such multi-product processes, based on the conversion of renewable materials into biobased products, are known as biorefineries [4].The study, development, and application of robust microbial strains, able to utilize a variety of substrates and to produce a wide range of products, is considered a milestone in the development of biorefineries [4]. Lactic acid bacteria (LAB) are a diverse group with recognized potential for the development of integrated biorefineries [5]. LAB are non-sporulating, non-motile, acid-tolerant, non-respiring but aerotolerant, catalase-negative, Gram-positive cocci or rods. They are characterized by the production of lactic acid (LA) as the major end metabolic product of carbohydrate fermentation [6][7][8][9]. Given the lack of a functional respiratory system, LAB obtain energy through substrate-level phosphorylation following two metabolic pathways for hexose fermentation, i.e., homofermentative and heterofermentative. As shown in Figure 1, the first pathway is based on glycolysis with the production of mainly LA, whereas the second one, known as the pentose phosphate pathway, is characterized for the production of CO 2 and ethanol, or acetate in addition to LA [6].

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Pigments of pericarp and pulp of pink guava (Psidium guajava L. cv. 'Criolla') were investigated to elucidate the profile and the accumulation of main carotenoids during four stages of fruit ripening by using HPLC-DAD and APCI-MS/MS analysis. Seventeen carotenoids were identified, and changes in their profile during fruit ripening were observed. The carotenoids all-trans-β-carotene, 15-cis-lycopene, and all-trans-lycopene were present in all ripening stages, but all-trans-lycopene was found to be predominant (from 63% to 92% of total carotenoids) and responsible for the high lipophilic antioxidant capacity determined by spectrophotometric assays. By using light and transmission electron microscopy, the development of chromoplasts in pericarp and pulp was demonstrated. The accumulation of all-trans-lycopene and all-trans-β-carotene coincided with the development of large crystals; the chromoplasts of pink guava belong, therefore, to the crystalline type.

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Major physicochemical and antioxidant changes during peach-palm (Bactris gasipaes H.B.K.) flour processing. Abstract-Introduction. Several studies have demonstrated that food processing affects nutrients such as bioactive compounds, protein, starch, fat, fiber, minerals and antioxidant capacity. Our study examined how heat changes the physicochemical composition and antioxidant capacity of peach-palm fruit (Bactris gasipaes H.B.K.) during flour production. Materials and methods. Five commercial batches of fruit were assessed for total contents of phenolic compounds and carotenoids, and hydrophilic oxygen radical absorbance capacity (H-ORAC). The fruit was then cooked and eventually processed into flour. Results and discussion. No significant changes were found for contents of fat, protein, starch and dietary fiber during flour production. Cooked peach-palm fruit is a source of Mg, Mn, Cu and K, with 100 g of fruit containing between 5% and 13.5% of the recommended daily intake. Cooking also increased carotenoids by 17%, thus helping to compensate for the 28% loss during drying. No stage of processing affected polyphenol contents or H-ORAC. Conclusion. Because of its high bioactive compound content, peach-palm flour shows potential for use in the development of functional foods. Costa Rica / Bactris gasipaes / fruits / processing / drying / proximate composition / carotenoids / polyphenols / antioxidants Principales modifications physico-chimiques et antioxydantes au cours de la fabrication de farine de pejibaie (Bactris gasipaes H.B.K.). Résumé-Introduction. Plusieurs études ont montré que la transformation des aliments affectait les nutriments tels que les composés bioactifs, protéines, amidon, graisses, fibres, minéraux, et la capacité antioxydante. Notre étude a examiné comment la chaleur modifiait la composition physico-chimique et la capacité antioxydante des fruits de pejibaie (Bactris gasipaes HBK) au cours de la production de farine. Matériel et méthodes. Cinq lots commerciaux de fruits ont été évalués pour leur contenu total en composés phénoliques et caroténoïdes, et leur capacité hydrophile d'absorption des radicaux oxygénés (H-ORAC). Les fruits ont ensuite été cuits et éventuellement transformés en farine. Résultats et discussion. Aucun changement significatif n'a été trouvé quant au contenu des fruits en matières grasses, protéines, amidon et fibres alimentaires durant la production de farine. Le fruit de pejibaie cuit est une source de Mg, Mn, Cu, et K, dont 100 g de fruits contiennent entre 5 % et 13,5 % de l'apport quotidien recommandé. La cuisson a permis également d'augmenter de 17 % la teneur en caroténoïdes, ce qui contribue à compenser la perte de 28 % observée lors du séchage. Aucune étape de la transformation n'a affecté les teneurs en polyphénols ou la valeur de H-ORAC. Conclusion. En raison de sa haute teneur en composés bioactifs, la farine de pejibaie est potentiellement intéressante à utiliser pour le développement d'aliments fonctionnels.

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Ultrasound is a useful alternative to thermal processing that can be applied to many food products and juices to aid with enzymes and microorganism inactivation and to improve the efficiency of unit operations generally applied in the food industry. The aim of this study was to evaluate the effect of a high-intensity sonication treatment (frequency 20 kHz; intensity 39.4 W/cm2) applied for treatment times from 0 to 105 min on the content of polyphenols, vitamin C, organic acids, and carotenoids, and on the hydrophilic and lipophilic antioxidant capacity and color of orange juice. Treatments were performed in triplicate and data was statistically analyzed. Sonication time did not have a significant effect ( P > 0.05) on total polyphenols, total vitamin C, organic acid, and carotenoid contents, lipophilic antioxidant capacity, or juice color. The hydrophilic antioxidant activity and the lutein content increased significantly ( P < 0.05) with increased sonication time. These results may be useful as a baseline for the development of sonication treatments that could be used in combination with other traditional and emerging processing approaches to protect the most important bioactive compounds and quality properties of orange juice.