Fruits, seeds and leaves of guabijuzeiro (Myrcianthes pungens (O. Berg) D. Legrand): characteristics, uses and health benefits.

Native fruit trees have potential for use in the food and pharmaceutical industries, which is widely used in folk medicine. Guabiju, known as guabijuzeiro (Myrcianthes pungens (O. Berg) D. Legrand) is a perennial tree that belongs to the family Myrtaceae, occurring in Brazil from São Paulo to Rio Grande do Sul, and other countries like Uruguay, Bolivia, Paraguay and Argentina. This species demonstrates great commercial potential regarding the consumption of its fresh fruit or industrialized. Due to its importance is necessary to develop studies aimed at characterization (phenotypic, propagative, reproductive, chemical and nutritional), uses and applications. However, the available information has never been systematized and in this sense the objective of this review is to compile information about the species to guide further research. Regarding morphology, the guabijuzeiro is a semi-deciduous tree species, with propagation is carried out mainly through seeds and vegetative. Regarding reproductive aspects, there is a lack of studies that assess the mode of reproduction. The fruit can be consumed fresh or processed as ice cream, juice, freeze-dried or dehydrated. It is sweet and slightly acidic, low in calories, high in carbohydrates, essential fatty acids, calcium and potassium. Both the fruit, the seed and the leaves have high levels of bioactive compounds and high antioxidant capacity. The fruit pulp stands out for its carotenoids and phenolic compounds and the peel is rich in anthocyanins, especially in the mature phase, in addition to terpenoids. M. pungens has antimicrobial effects, gastroprotective activity and is promising in the prevention of neurodegenerative diseases and against the side effects of cisplatin, an anticancer agent. Finally, there is a need for further studies with this species, mainly in the characterization of the leaves, uses and applications of the fruit.

Peppermint essential oil volatiles as natural alternative to prevent potato sprouting induced by gibberellic acid.

The objective was to evaluate the effect of peppermint essential oil (PEO) on the inhibition of potato sprouting induced by gibberellic acid (GA) during storage. PEO (0.08 and 0.15 mL L-1) was applied in the presence and absence of gibberellic acid (10 mg L-1). The presence of phytopathogens and changes in breaking of dormancy, weight loss, moisture content, and total soluble solids were measured during 28 days. The inhibition of potato sprouting by the PEO occurred at the lowest concentration, even in the presence of GA. Sprout development was inhibited with PEO addition, delaying the dormancy break and reducing weight loss. However, potato sprouting was still inhibited after the removal of the PEO, evidencing its residual efficacy. PEO application at both concentrations had a satisfactory effect on sprout suppression and can be used as a promising eco-friendly approach for inhibiting the sprouting of potato tubers during storage.

Characterization of ultrafine zein fibers incorporated with broccoli, kale, and cauliflower extracts by electrospinning.

BACKGROUND: Broccoli, kale, and cauliflower contain phenolic compounds and glucosinolates, which have several biological effects on the body. However, because they are thermolabile, many of these substances are lost in the cooking process. Electrospinning encapsulation, using zein as a preservative wall material, can expand the applications of the compounds in the food and pharmaceutical industries. The objective of this research was to characterize broccoli, kale, and cauliflower extracts and encapsulate them with the electrospinning technique using zein. RESULTS: Broccoli, kale, and cauliflower extracts contain five phenolic compounds and three glucosinolates. Fibers from broccoli, kale, and cauliflower showed high encapsulation efficiency, good thermal stability, and nanometric size, especially those containing extract and zein in proportions of up to 35:65. CONCLUSION: Fibers from broccoli, kale, and cauliflower containing extract and zein in proportions of up to 35:65 have the potential for effective nutraceutical application for the control of non-communicable chronic diseases or application in food packaging. © 2022 Society of Chemical Industry.

Polysaccharides as wall material for the encapsulation of essential oils by electrospun technique.

Electrospinning is a versatile, inexpensive and reliable technique for the synthesis of nanometric fibers or particles from polymeric solutions, under a high voltage electric field. The use of natural polysaccharides such as starch, chitosan, pectin, alginate, pullulan, cellulose and dextran as polymeric materials allows the formation of biodegradable fibers and capsules. Bioactive compounds extracted from natural sources, such as essential oils, have been widely studied due to their antioxidant, antimicrobial and antifungal properties. The combination of natural polymers and the electrospinning technique allows the production of structures capable of incorporating these bioactive compounds, which are highly sensitive to degradation reactions. This review describes several approaches to the development of nanofibers and nanocapsules from polysaccharides and the possibility of incorporating hydrophobic compounds, such as essential oils. The review also discusses the use of electrosprayed products incorporated with essential oils for direct application in food or for use as active food packaging.

Impact of encapsulated orange essential oil with ß-cyclodextrin on technological, digestibility, sensory properties of wheat cakes as well as Aspergillus flavus spoilage.

BACKGROUND: The majority of studies with essential oils in foods focus mainly on improving the shelf life of products; however, the present study goes further and demonstrates not only the effect of essential oil on conservation properties, but also the effect of free and encapsulated orange essential oil (OEO) on the technological, sensorial and digestibility properties of bakery products. RESULTS: OEO was encapsulated into ß-cyclodextrin (ß-CD) by inclusion complex formation (ß-CD/OEO 97.4% of encapsulation efficiency). OEO demonstrated in vitro antifungal activity against Aspergillus flavus (inhibition zone of 11.33 mm on mycelial growth). In situ antifungal activity against A. flavus confirmed that free OEO can effectively delay the fungal growth, unlike encapsulated OEO. Regarding texture profile and starch digestibility: cake with ß-CD/OEO showed lower hardness (31.64 N) and lower starch digestibility (69.10%) than cake with free OEO (44.30 N; 82.10%, respectively) and the addition of OEO (both free and encapsulated) decreased the adhesiveness of the cakes. Cake with free OEO showed a higher intensity of orange aroma, being preferred by 60% of panelists, whereas cake with ß-CD/OEO presented a very slight orange taste and aroma. CONCLUSION: The encapsulation of OEO into ß-CD improved the crumb texture of cakes and promoted a lower starch digestibility in the cakes. On the other hand, the encapsulation process was not effective under the conditions tested (OEO concentration and baking temperatures), compromising the action of the OEO as a natural flavoring and preservative agent. © 2021 Society of Chemical Industry.

Carioca bean starch upon synergic modification: characteristics and films properties.

BACKGROUND: The use of damaged beans for starch isolation comprises an end-use alternative for a product that is not accepted by the consumer. For that reason, isolation and modification of Carioca bean starch should be explored and evaluated as a suitable source for biodegradable material. The present study aimed to evaluate the synergism of physical and chemical modifications on Carioca bean starch with respect to improving the properties of biodegradable films. A heat-moisture treatment (HMT) followed by oxidation by sodium hypochlorite was performed and vice versa. RESULTS: Synergism was noted in the starch properties compared to the single modification. When the oxidation was applied first, a higher amylose and carbonyl content was noted. HMT, isolated and as a second modification, caused a more pronounced effect on viscosity profile than the oxidized starch, with an increase in paste temperature and a decrease in viscosity, breakdown and final viscosity. CONCLUSION: The results obtained in the present study reflect a decrease in water vapor permeability, although a higher tensile strength was noted when oxidation was applied, as a single and as a first modification. © 2020 Society of Chemical Industry.

Starch nanofibers as vehicles for folic acid supplementation: thermal treatment, UVA irradiation and in vitro simulation of digestion.

BACKGROUND: The supplementation of folic acid in food is essential in the human diet. The present study aimed to encapsulate folic acid at different concentrations (5, 10 and 15% (w/w) on a dry basis) in potato starch nanofibers produced through electrospinning. The starch/folic acid nanofibers were evaluated through morphology, Fourier transform infrared (FTIR) spectra, thermal properties, encapsulation efficiency (EE) and in vitro simulation of the human digestion. The nanofibers were also evaluated based on the folic acid content after thermal treatment (100 and 180 °C) and UVA irradiation (1 and 24 h). RESULTS: Folic acid incorporation influenced the morphology of the nanofibers to display a homogeneous and beadless morphology for nanofibers containing 15% folic acid compared with the other nanofibers (0, 5 and 10% folic acid). The mean diameter varied from 75 to 81 nm. Folic acid characteristic bands and peaks were not found in the nanofiber FTIR spectra and thermograms, respectively. The EE was 73, 87 and 95% for nanofibers with 5, 10 and 15% folic acid, respectively. CONCLUSIONS: The starch nanofibers protected folic acid from high temperature and UVA irradiation and during in vitro digestion, showing a release of the vitamin at the end of the simulation (intestinal conditions). The supplementation of folic acid in foods can be effectively achieved by its encapsulation into starch nanofibers, to ensure its protection and controlled release. © 2020 Society of Chemical Industry.

Encapsulation of broccoli extract by electrospraying: Influence of in vitro simulated digestion on phenolic and glucosinolate contents, and on antioxidant and antihyperglycemic activities.

Compounds present in broccoli are vulnerable to the digestive process, and encapsulation becomes an alternative for their preservation. The encapsulation of broccoli extract, by electrospraying, was performed with the purpose of evaluating the effect of in vitro simulated digestion on individual compounds and antioxidant and antihyperglycemic potentials. Each digestion fraction was evaluated by chromatography, as well as for antioxidant activity and antihyperglycemic potential. The encapsulated extract showed high encapsulation efficiency and spherical morphology. Losses in the levels of phenolic compounds and glucosinolates were found in both extracts, considering the fractions submitted to digestion. The digestion promoted an increase in the inhibition of hydroxyl, nitric oxide and α-amylase, as well as a decrease in the inhibition of α-glucosidase in both extracts, when compared to undigested fractions. Thus, the digestion affects the compounds content in both encapsulated and unencapsulated extracts. However, they still promote the control of oxidative processes and hyperglycemia.

Antimicrobial potential of spray drying encapsulated thyme (Thymus vulgaris) essential oil on the conservation of hamburger-like meat products.

Synthetic preservatives can have harmful effects on the body, so plant essential oils appear to be an attractive natural alternative. However, the use of essential oils is limited due to the low stability and possible negative effects on the sensory properties of food. Oil encapsulation was suggested as a way to overcome these drawbacks. The objective of this study was to encapsulate thyme essential oil and to evaluate its antioxidant and antimicrobial potential in vitro and in situ in of hamburger-like meat products. The casein-maltodextrin capsules produced by spray-drying were assessed for encapsulation efficiency, thermal stability, chemical compounds and morphology. Antioxidant activity was evaluated by DPPH, hydroxyl and nitric oxide methods, while antimicrobial activity was evaluated in vitro against four bacteria and in situ in hamburger-like products. The capsule showed high encapsulation efficiency and thermal stability, and spherical and irregular morphology. The casein-maltodextrin encapsulated essential oil showed antioxidant and antimicrobial activity against Staphylococcus aureus, Escherichia coli, Listeria monocytogenes and Salmonella Typhimurium tested in vitro and against thermotolerants coliforms and Escherichia coli in situ, showing potential for application as a natural preservative in food.

Electrospun potato starch nanofibers for thyme essential oil encapsulation: antioxidant activity and thermal resistance.

BACKGROUND: Thyme essential oil (TEO) is an excellent natural substitute for synthetic compounds to maintain the quality and safety of food products. It acts as an antioxidant agent. We aimed to nanoencapsulate TEO at concentrations of 1%, 3%, and 5% (v/w, dry basis) in electrospun nanofibers made of starch (50% w/v) and formic acid (75% v/v). The rheological parameters of the fiber-forming solutions were measured, and various physical and chemical properties of the nanofibers were analyzed. RESULTS: The starch/TEO nanofibers presented homogeneous morphology. The starch nanofibers showed high encapsulation efficiency (EE, 99.1% to 99.8%), which, along with the Fourier transform infra-red (FTIR) spectrum and thermogravimetric analysis (TGA) analysis, indicate strong protection of the phenolic compounds of TEO. Nanofibers with 5% TEO retained up to 50% of the phenolic compounds after exposure to thermal treatment. The antioxidant activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals of the starch/TEO nanofibers varied from 11.1% to 14.2% and the inhibition values (29.8%, P ≤ 0.05) against hydroxyl radicals were the same for free TEO and the nanofibers. CONCLUSION: Owing to these properties, electrospun starch/TEO nanofibers can be applied in food products or food packaging.

Glucosinolates and phenolic compounds rich broccoli extract: Encapsulation by electrospraying and antitumor activity against glial tumor cells.

Gliomas, intracranial malignant tumors, are aggressive, asymptomatic and difficult to treat due to their degree of infiltration, alternatives are needed to treat the disease. In this sense, natural compounds from the specialized metabolism of plants can act to control the disease. Glucosinolates and phenolic compounds, present in broccoli, have a potential to promote tumor cell death, however due to the low stability of these compounds, encapsulation becomes an alternative for their preservation. The objective was to encapsulate the broccoli extract by electrospraying and to evaluate its cytotoxicity in the primary cell culture of astrocytes and gliomas. The capsules were produced and characterized by encapsulation efficiency, functional groups, thermal stability and morphology, the capsule that presented the best parameters was used for the evaluation of cell cytotoxicity and antitumor activity. Capsules with equal or less than 50 % extract showed high encapsulation efficiency, high thermal stability and uniform morphology due to non-saturation of the active zein sites, which allowed a complete encapsulation of the added extract, as well as a greater protection of the compounds. The capsule with 50 % of the extract showed good results of the efficiency, morphology and thermal stability and was used to evaluate the antitumor activity, since the addition of extract in proportions greater than 60 % promoted saturation of the active sites and lower encapsulation efficiency, and directly affects the morphology and thermal stability. The encapsulated and unencapsulated extracts showed strong selective antitumor effect against glial tumor cells without toxicity to non-tumor cells.

Dual modification of potato starch: Effects of heat-moisture and high pressure treatments on starch structure and functionalities.

This study investigated the association of heat moisture treatment (HMT) with high hydrostatic pressure (HHP) and evaluated its effects on the thermal, pasting, swelling power, solubility, morphology, and crystallinity characteristics, as well as in vitro digestibility of potato starch. The single and dual modifications significantly altered the pasting properties of potato starch except for HHP. When HHP was applied to HMT starches, the peak viscosities, setback, and final viscosities were greatly increased compared to those of the samples processed with HMT alone. Dual modification increased the transition temperatures, swelling power, and altered the relative crystallinity. The modified starch exhibited a slower rate of glucose release which decreased proportionally with increasing moisture in the HMT. Dual modification showed a remarkable ability to modify starches with different characteristics and can be used as an alternative in the elaboration of low glycaemic index foods.

Physically cross-linked aerogels based on germinated and non-germinated wheat starch and PEO for application as water absorbers for food packaging.

The objective of this study was to generate and characterize physically cross-linked aerogels by using germinated and non-germinated wheat starch, with and without the addition of poly (ethylene oxide) (PEO). Aerogels were produced by gelatinization of starch (10% w/v, in distilled water) at 90 °C, followed by multiple freeze/thaw cycles. For the aerogel produced using starch and PEO, a solution of 6% PEO (0.6 g of PEO/10 mL of distilled water) was added to the dispersion. The thermal properties, infrared spectra, relative crystallinity, morphology, water absorption properties, and texture profile of the aerogels were evaluated. After immersion in water for 24 h, the aerogels exhibited high degradation temperature, water absorption capacity, and physical integrity. Aerogels produced using the germinated wheat starch were much more integrated structurally compared to the aerogels produced using the non-germinated wheat starch. Wheat germination did not have any impact on the textural parameters of the aerogels. However, addition of PEO increased the water absorption capacity and reduced the hardness and cohesion of the resulting aerogels. Due to the high water absorption potential, the aerogel produced in this study can serve as an absorbent matrix in food packaging.

Electrospun protein fibers loaded with yerba mate extract for bioactive release in food packaging.

BACKGROUND: Yerba mate extract was encapsulated in electrospun zein fibers. Solutions were prepared with 30% (w/v) zein, and yerba mate extract was added at concentrations of 1%, 3%, and 5% (w/w). The rheology and electrical conductivity of the polymer solutions were evaluated. The extract and the fibers were characterized through an analysis of total and individual phenolic compounds, antioxidant activity, and Fourier-transform infrared (FTIR) spectra. Morphology, size distribution, and thermal stability were also evaluated. The release kinetics of zein fibers loaded with different concentrations of yerba mate were evaluated in a hydrophilic food-simulant medium (10% ethanol). RESULTS: Yerba mate extract had a total phenolic compound content of 1287.76 ± 11.55 mg of gallic acid 100 g-1 yerba mate extract. The major individual phenolic compounds obtained were chlorogenic acid and rutin, quantified by high-performance liquid chromatography and mess spectrometry (HPLC-MS). Zein fibers loaded with 5% extract exhibited higher antioxidant activity with 83.0% inhibition. The fibers with different concentrations of yerba mate displayed homogeneous morphology. Yerba mate extract encapsulated in zein fibers had greater thermal stability than the free extract. Zein fibers comprising 5% yerba mate extract, when in contact with a hydrophilic food simulant medium, showed a release of approximately 49% of extract within 50 h. CONCLUSION: Zein fibers containing yerba mate extract may be used as antioxidant releasers for food packaging. © 2020 Society of Chemical Industry.

Antibacterial activity, optical, mechanical, and barrier properties of corn starch films containing orange essential oil.

The incorporation of antimicrobial compounds into natural polymers can promote increased shelf life and ensure food safety. The aim of this study was to evaluate the antibacterial activity, morphological, optical, mechanical, and barrier properties of corn starch films containing orange (Citrus sinensis var. Valencia) essential oil (OEO). The corn starch films were prepared using the casting method. OEO and the corn starch films incorporated with OEO showed higher antibacterial activity against Staphylococcus aureus and Listeria monocytogenes. The addition of OEO to the films increased the morphological heterogeneity and contributed to the reduction of the tensile strength and elongation of the films, and it increased the moisture content, water solubility, and water vapor permeability. The water vapor permeability and partial or total solubility of a film in water prior to consumption of a product are of interest when the film is used as food coating or for encapsulation of specific molecules.

Electrospinning of native and anionic corn starch fibers with different amylose contents.

Through starch phosphorylation and solution aging treatments, the aim of this work was to produce electrospun fibers derived from native and anionic (modified with sodium tripolyphosphate) corn starches with amylose contents of <70% (w/w). The fibers of native and anionic corn starches (regular amylose and high amylose Hylon V/Hylon VII) were prepared by electrospinning of starch solutions dissolved in aqueous 75% formic acid (v/v) solvent. The effects of the aging (24, 48, and 72 h) on the rheology and electrical conductivity of the starch solutions, as well as the material properties (size distribution, morphology, and infrared spectrum) of the resulting electrospun fibers, were evaluated. Fibers produced from Hylon VII and Hylon V starches showed homogeneous morphologies, whereas the fibers from regular corn starches exhibited droplets and had heterogeneous morphologies, with diameter varied from 70 to 264 nm. Both native and anionic corn starches, with amylose contents of <70% (w/w), produced smooth continuous fibers. The electrospun corn starch fibers potentially can be used as carriers for the encapsulation of active components in food and packaging applications.

Immobilization of α-amylase in ultrafine polyvinyl alcohol (PVA) fibers via electrospinning and their stability on different substrates.

The objective of this study was to immobilize α-amylase in ultrafine polyvinyl alcohol (PVA) fibers by electrolysis and to evaluate its stability at different temperatures and pHs using various starch substrates such as corn starch and germinated and ungerminated wheat starches. The α-amylase-loaded ultrafine fibers were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and loadability and enzymatic activity evaluations. Incorporation of the enzyme resulted in a slight change in fiber morphology; the fibers became flatter and thicker with increasing enzyme concentration. The mean diameters ranged from 187 to 282 nm. FT-IR spectra indicated that the enzyme was incorporated into the fibers. PVA showed a high loading capacity for α-amylase at all concentrations tested (1.0, 1.5, and 2.0% w/v), indicating that PVA is an excellent support. The enzymatic activity of α-amylase was tested on the different starch substrates; the activity was higher in the immobilized form than in the free form. Enzymatic immobilization improved the stability of α-amylase over a wide range of temperatures and pHs. Enzymatic activity was highest when germinated wheat starch was used as the substrate at different temperatures and pHs, indicating great potential for its application in hydrolysis with α-amylase.

Physicochemical, pasting, crystallinity, and morphological properties of starches isolated from maize kernels exhibiting different types of defects.

The present study aims to evaluate the physicochemical, rheological, and safety properties of starches isolated from maize kernels with different types of defects. Starch isolation showed to be a valuable alternative to defective yellow maize kernels, since the presence of the evaluated kernel defects (broken, fermented, rotten, moldy, germinated, insect-damaged, and shrunken and immature kernels) did not provide significant changes on starch purity and colour. Only starch isolated from shrunken and immature kernels exhibited reduced extractability. Starch obtained from germinated kernels exhibited the greatest solubility. While flour from moldy kernels showed 7.5 ppb of aflatoxin A1, 25.0 ppb of aflatoxin A2, and 1229.4 ppb of fumonisin B1, any of these mycotoxins were detected in isolated starch. In sum, minor changes in pasting, thermal, crystallinity, and morphological properties of the isolated starches from defective kernels were determined, which does not impair its use in industrial processes.

Antimicrobial electrospun ultrafine fibers from zein containing eucalyptus essential oil/cyclodextrin inclusion complex.

The aim of this study was to produce ultrafine fibers from zein incorporated with a complex of eucalyptus essential oil (EEO) and ß-cyclodextrin (ß-CD) with antimicrobial properties by electrospinning technique. The EEO was characterized by chemical composition and antimicrobial tests against three Gram positive and four Gram negative bacteria. The inclusion complex (IC) was prepared with ß-CD and EEO by co-precipitation technique and added at different concentrations in zein polymer solution using aqueous ethanol as solvent. The morphology, thermal properties, functional groups, and antimicrobial activity against L. monocytogenes and S. aureus of the ultrafine fibers were evaluated. The composite membranes containing 24% IC exhibited a greater reduction of growth as compared to the fibers without addition of IC. For L. monocytogenes the growth reduction was 28.5% and for S. aureus it was 24.3%. The electrospun IC-ß-CD/EEO composite membranes are promising for use in antimicrobial applications, such as food packaging.

Molecular structure, functionality and applications of oxidized starches: A review.

During oxidation, the hydroxyl groups of starch molecules are first oxidized to carbonyl groups, then to carboxyl groups. The contents of the carbonyl and carboxyl groups in a starch molecule therefore indicate the extent of starch oxidation. The mechanisms of starch oxidation with different oxidizing agents, including sodium hypochlorite, hydrogen peroxide, ozone and sodium periodate, are described in this review. The effects of these oxidizing agents on the molecular, physicochemical, thermal, pasting and morphological properties of starch are described as well. In addition, the main industrial applications of oxidized starches are presented. The present review is important for understanding the effects of oxidation on starch properties, and this information may facilitate the development of novel oxidized starches for both food and non-food applications.