Bioactive compounds and antioxidant activities in the agro-industrial residues of acerola (Malpighia emarginata L.), guava (Psidium guajava L.), genipap (Genipa americana L.) and umbu (Spondias tuberosa L.) fruits assisted by ultrasonic or shaker extraction

Acerola processing waste: Convective drying with ethanol as pretreatment

The acerola seed is an agro-industrial waste. It is a high moisture content product, rich in bioactive compounds. Drying is an alternative to make this waste available in a safe condition. The use of ethanol as a pretreatment could improve the drying process besides reducing the operation time. This study aimed to investigate the influence of ethanol pretreatment (ET) on the content of bioactive compounds, cell wall thickness, and color. The drying kinetics was studied, and the influence of external and internal resistance was discussed. The samples were immersed in ethanol for 2 min with subsequent convective drying (40 °C and 60 °C; 1 m s-1) until they reached the equilibrium condition. The ET reduced the drying time up to 36.36 %. The external and mixed control of mass transfer were identified as the governing regimes for drying this material, depending on the use of ethanol. ET led to an increase in effective diffusivity, a reduction in cell wall thickness, and preservation of the color of the dried waste. The ET positively impacted the conservation of ascorbic acid compared to untreated dried samples but was not relevant to phenolic compounds, carotenoids, and antioxidant activity. The drying process increased the bioactivity of the anthocyanins. The best condition was drying at 60 °C, pretreated with ethanol.

Agro-Industrial By-Products of Plant Origin: Therapeutic Uses as well as Antimicrobial and Antioxidant Activity

The importance of bioactive compounds in agro-industrial by-products of plant origin lies in their direct impacts on human health. These compounds have been shown to possess antioxidant, anti-inflammatory, and antimicrobial properties, contributing to disease prevention and strengthening the immune system. In particular, the antimicrobial action of these compounds emerges as an important tool in food preservation, providing natural alternatives to synthetic preservatives and contributing to combating antimicrobial resistance. Using agro-industrial by-products of plant origin not only addresses the need to reduce waste and promote sustainability but also inaugurates a new era in the formulation of functional foods. From fruit peels to pulps and seeds, these by-products are emerging as essential ingredients in the creation of products that can promote health. Continued research in this area will unveil new applications and properties of these by-products and open doors to a food paradigm in which health and sustainability converge, paving the way to a healthier and more equitable future. The present review presents an overview of our knowledge of agro-industrial by-products and some of their more relevant health-promoting bioactivities.

Fermenting Acerola (Malpighia emarginata D.C.) and Guava (Psidium guayaba L.) Fruit Processing Co-Products with Probiotic Lactobacilli to Produce Novel Potentially Synbiotic Circular Ingredients

This study evaluated the effects of acerola and guava fruit processing co-products fermented with probiotic Lactobacillus acidophilus LA-05 and Lacticaseibacillus paracasei L-10 on the abundance of different intestinal bacterial groups and microbial metabolic activity during 48 h of in vitro fecal fermentation. Digested fermented fruit co-products increased the relative abundance of beneficial bacterial groups while overall decreasing or maintaining the relative abundance of non-beneficial bacterial groups, suggesting selective stimulatory effects on beneficial bacterial intestinal populations. The fermented co-products stimulated microbial metabolic activity due to decreased pH, sugar consumption, short-chain fatty acid production, phenolic compound and metabolic profile alteration, and high antioxidant capacity during fecal fermentation. Acerola and guava co-products have high nutritional value and bioactive compounds whose fermentation with probiotics improves their potential functionalities. The results show that fermented fruit co-products could induce beneficial changes in the relative abundance of several bacterial groups as well as in the metabolic activity of the human intestinal microbiota. These results highlight their potential as novel and circular candidates for use as synbiotic ingredients.

Intelligent and active biodegradable biopolymeric films containing carotenoids

There is growing interest in the use of natural bioactive compounds for the development of new bio-based materials for intelligent and active food packaging applications. Several beneficial effects have been associated with the antioxidant and antimicrobial potentials of carotenoid compounds. In addition, carotenoids are sensitive to pH changes and oxidation reactions, which make them useful bioindicators of food deterioration. This review summarizes the current research on the application of carotenoids as novel intelligent and active biodegradable food packaging materials. Carotenoids recovered from food processing by-products can be used in the development of active food packaging materials due to their antioxidant properties. They help maintain the stability of lipid-rich foods, such as vegetable oils. Additionally, when incorporated into films, carotenoids can monitor food oxidation, providing intelligent functionalities.

Acerola (Malpighia emarginata) Anti-Inflammatory Activity-A Review

The manuscript provides an overview of recent scientific reports on the properties and range of health-promoting effects of acerola (Malpighia emarginata DC) fruits and leaves. Acerola is a natural raw material that, in its unprocessed form, is known to be a rich source of vitamin C and polyphenolic compounds. For this reason, the consumption of acerola may provide a number of health-promoting benefits, particularly related to its strong anti-free radical effects. The review discusses anti-inflammatory and anticancer effects of acerola fruit and leaves as well as its therapeutic effects on selected physiological processes in the human system. Their biochemical mechanisms are also explained. Recommendations for the consumption of acerola in the prevention of inflammatory and free radical diseases are presented. The part of the article devoted to anticancer effects of acerola describes the possibilities of using the edible parts of this raw material to obtain products and preparations of potential use in cancer prevention and therapy.

Flours from Spondias mombin and Spondias tuberosa seeds: Physicochemical characterization, technological properties, and antioxidant, antibacterial, and antidiabetic activities

Yellow mombin (Spondias mombin) and Brazil plum (Spondias tuberosa) seeds are byproducts of exploiting their pulp and currently have no relevant food or industrial applications. Thus, the present study aimed to evaluate the physicochemical, technological, and functional characteristics of flours obtained from yellow mombin (YMF) and Brazil plum (BPF) residues. The flours presented a high percentage of insoluble fiber (68.8-70.2 g/100 g) and low carbohydrate (2.7-4.0 g/100 g) and caloric (91.9-95.3 kcal) values. The flours showed potential for technological application. In addition, the highest concentration of total phenolic content (31.1-50.2 mg GAE/g) was obtained with 70% acetone, which provided excellent results for antioxidant capacity evaluated by 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (81.0%-89.7%) and 2,2-diphenyl-1-picrylhydrazyl (60.6%-69.1%) radical scavenging capacity assays. Flour extracts in 70% acetone also exhibited inhibition of α-amylase (63.3%-78.8%) and amyloglucosidase (63.5%-71.0%). The antibacterial study revealed that extracts inhibited the growth of Escherichia coli, Burkholderia cepacia, and Burkholderia multivorans. Therefore, this study suggests the use of yellow mombin and Brazil plum residues for different food or industrial applications. PRACTICAL APPLICATION: The knowledge gained from this study will open a new approach to add value to yellow mombin and Brazil plum fruit seeds as sources of fiber and bioactive compounds, with promising application in the formulation of functional and nutraceutical products, benefiting both a sustainable environment and a sustainable industry.

Spondias sp: Shedding Light on Its Vast Pharmaceutical Potential

Many plants are used by the population through popular knowledge passed from generation to generation for the treatment of various diseases. However, there is not always any scientific content supporting these uses, which is very important for safety. One of these plants is the fruit of the Spondias genus, which during its processing generates various residues that are discarded, but which also have pharmacological properties. The focus of this review is to survey the pharmacological activities that Spondias genus shows, as well as which part of the plant is used, since there is a lot of richness in its by-products, such as leaf, bark, resin, seed, and peel, which are discarded and could be reused. The main activities of this genus are antioxidant, anti-inflammatory, antidiabetic, antifungal, and antiviral, among others. These properties indicate that this genus could be used in the treatment of several diseases, but there are still not many products available on the market that use this genus as an active ingredient.

Effects of Pectinase Pre-Treatment on the Physicochemical Properties, Bioactive Compounds, and Volatile Components of Juices from Different Cultivars of Guava

In this study, the physicochemical properties, antioxidant capacity, and volatile compounds of the juices of different guava cultivars before and after pectinase treatment were evaluated. The results showed that the guava juice of the small fragrant (SF) cultivar exhibited the highest ascorbic acid concentration (1761.09 mg/L), and the highest contents of total phenolics (329.52 mg GAE/L) and total flavonoids (411.13 mg RE/L) were both found in the juice of the watermelon red (WR) cultivar. After pectinase treatment, the juice yield and the titratable acid, sugar components, total phenolics and total flavonoids, and antioxidant capacity levels of the guava juices were all higher than those of the non-pectinase group. However, lower sensory evaluation scores were obtained in the pectinase-treated guava juices. Aldehydes and terpenoids were the main flavor components in the guava juices, which were responsible for the aroma of the juice, while their relative contents were different in the four cultivar guava juices. Furthermore, pectinase treatment could change the amounts and relative contents of volatile compounds in the guava juice. During the pectinase treatment process, the relative contents of the main aroma constituents in the guava juices were significantly decreased. The findings of this research provide valuable information for the processing of guava juice.

Antioxidant Extracts of Nettle (Urtica dioica) Leaves: Evaluation of Extraction Techniques and Solvents

Nettle (Urtica dioica) is a great source of bioactive compounds. The objective of this study was to evaluate the extraction techniques (ultrasound, without stirring, and stirring), solvents (methanol, water, and ethanol), and extraction times (1–4 h) to maximize antioxidant capacity of the Urtica dioica extracts. In the case of total phenolic content (TPC) and ABTS^•+ (2,2-azino-bis(3-etilbenzotiazolin)-6-sulfonic acid) free radical scavenging values, ultrasound extraction was the most efficient method, while the best results of DPPH^• (1,1-diphenyl-2-picrylhydrazyl) assay in nettle extracts (91.08%) were obtained using stirring extraction, water as solvent, and 3 h of extraction time. Based on the obtained mathematical models, the optimization revealed that the best extraction conditions were ultrasound treatment with water as solvent and an extraction time of 3.15 h, obtaining values of 21.9 mg eq gallic acid/g dried nettle for TPC, 71.8% for %ABTS^•+ and 86.6% for %DPPH^•. This work proves that aqueous extract of nettle leaves through the ultrasound technique is an important source of natural antioxidants and can be considered a potential alternative to synthetic antioxidants.

Sustainable Food Systems: The Case of Functional Compounds towards the Development of Clean Label Food Products

The addition of natural components with functional properties in novel food formulations confers one of the main challenges that the modern food industry is called to face. New EU directives and the global turn to circular economy models are also pressing the agro-industrial sector to adopt cradle-to-cradle approaches for their by-products and waste streams. This review aims to present the concept of “sustainable functional compounds”, emphasizing on some main bioactive compounds that could be recovered or biotechnologically produced from renewable resources. Herein, and in view of their efficient and “greener” production and extraction, emerging technologies, together with their possible advantages or drawbacks, are presented and discussed. Μodern examples of novel, clean label food products that are composed of sustainable functional compounds are summarized. Finally, some action plans towards the establishment of sustainable food systems are suggested.

Ultrasound-Assisted Extraction of Natural Pigments From Food Processing By-Products: A Review

Ultrasound is an emerging technology, which has been highly explored in the food area to improve processes and products. When ultrasound is applied to a product with solid or fluid characteristics, the passage of acoustic waves and acoustic cavitation generates different mechanisms responsible for modifications in the original matrix of the sample. These effects of ultrasound can also be used to take advantage of by-products, for example by extracting compounds of interest, including natural pigments. Natural pigments or colorants are being highly demanded by different industries not only for color purposes but also due to their healthy properties, the greater demands in regulations and new consumer preferences. This review presents an updated critical analysis of the application of ultrasound-assisted extraction (UAE) to obtain natural pigments from food processing by-products. Initially, the ultrasound effects and mechanisms that improve the extraction of natural pigments in a fluid medium, as well as the factors that influence the extraction and the energy consumption of UAE are analyzed and described. Subsequently, the UAE application to obtain pigments belonging to the groups of carotenoids, chlorophyll, anthocyanins and betalains is evaluated. These sections detail the processing conditions, positive and negative effects, as well as possible applications of the extracted pigments. This review presents relevant information that may be useful to expand and explore new applications of ultrasound technology as well as promote the revaluation of by-products to obtain pigments that can be used in food, pharmaceutical or cosmetic industries.

Phenolic Compound Profile by UPLC-MS/MS and Encapsulation with Chitosan of Spondias mombin L. Fruit Peel Extract from Cerrado Hotspot-Brazil

Taperebá (Spondias mombin L.) is a native species of the Brazilian Cerrado that has shown important characteristics such as a significant phenolic compound content and biological activities. The present study aimed to characterize the phenolic compound profile and antioxidant activity in taperebá peel extract, as well as microencapsulating the extract with chitosan and evaluating the stability of the microparticles. The evaluation of the profile of phenolic compounds was carried out by UPLC-MS/MS. The in vitro antioxidant activity was evaluated by DPPH and ABTS methods. The microparticles were obtained by spray drying and were submitted to a stability study under different temperatures. In general, the results showed a significant content of polyphenols and antioxidant activity. The results of UPLC-MS/MS demonstrated a significant content of polyphenols in taperebá peel, highlighting the high content of ellagic acid and quercetin compounds. There was significant retention of phenolic compounds when microencapsulated, demonstrating high retention at all evaluated temperatures. This study is the first to microencapsulate the extract of taperebá peel, in addition to identifying and quantifying some compounds in this fruit.

Spray-Drying Microencapsulation of Pink Guava (Psidium guajava) Carotenoids Using Mucilage from Opuntia ficus-indica Cladodes and Aloe Vera Leaves as Encapsulating Materials

In this work, the capacity of the mucilage extracted from the cladodes of Opuntia ficus-indica (OFI) and aloe vera (AV) leaves as wall material in the microencapsulation of pink guava carotenoids using spray-drying was studied. The stability of the encapsulated carotenoids was quantified using UV-vis and HPLC/MS techniques. Likewise, the antioxidant activity (TEAC), color (CIELab), structural (FTIR) and microstructural (SEM and particle size) properties, as well as the total dietary content, of both types of mucilage microcapsules were determined. Our results show that the use of AV mucilage, compared to OFI mucilage, increased both the retention of β-carotene and the antioxidant capacity of the carotenoid microcapsules by around 14%, as well as the total carotenoid content (TCC) by around 26%, and also favors the formation of spherical-type particles (Ø ≅ 26 µm) without the apparent damage of a more uniform size and with an attractive red-yellow hue. This type of microcapsules is proposed as a convenient alternative means to incorporate guava carotenoids, a natural colorant with a high antioxidant capacity, and dietary fiber content in the manufacture of functional products, which is a topic of interest for the food, pharmaceutical, and cosmetic industries.

Umbu Fruit Peel as Source of Antioxidant, Antimicrobial and α-Amylase Inhibitor Compounds

Herein, the extraction of bioactive compounds from umbu fruit peel was optimized using thermal-assisted solid-liquid extraction. In parallel, antioxidant, antimicrobial, and inhibitory effects against α-amylase of optimized extract were also evaluated. The combination of operational conditions including the temperature (32-74 °C), ethanol concentration (13-97%), and solid/liquid ratio (1:10-1:60; w/v) was employed using a rotational central composite design for optimization. The extracts were evaluated for total phenolic compounds (TPC), total flavonoid compounds (TFC) and antioxidant capacity by ABTS•+, DPPH• and FRAP assays. The bioactive profile of the optimized extract was obtained by ultra-performance liquid chromatography coupled to quadrupole/time-of-flight mass spectrometry in electrospray ionization in both negative and positive modes. The statistically evaluated results showed that the optimal operational conditions for the recovery of bioactive compounds from umbu fruit peel included 74 °C, 37% ethanol, and a solid-liquid ratio of 1:38. Under these conditions, the obtained values were 1985 mg GAE/100 g, 1364 mg RE/100 g, 122 µmol TE/g, 174 µmol/TE g and 468 µmol Fe2+/g for TPC, TFC, ABTS•+, DPPH•, and FRAP assays, respectively. In addition, the optimized extract was effective against Gram-positive and Gram-negative bacteria (MBC ranged from 0.060 to 0.24 mg GAE/mL), as well as it was effective to inhibit α-amylase (IC50 value of 0.076 mg GAE/mL). The optimized extract showed to be mainly constituted by phenolic acids and flavonoids.