Hibiscus acetosella: An Unconventional Alternative Edible Flower Rich in Bioactive Compounds.

The interest in the consumption of edible flowers has increased since they represent a rich source of bioactive compounds, which are significantly beneficial to human health. The objective of this research was to access the bioactive compounds and antioxidant and cytotoxic properties of unconventional alternative edible flowers of Hibiscus acetosella Welw. Ex Hiern. The edible flowers presented pH value of 2.8 ± 0.00, soluble solids content of 3.4 ± 0.0 °Brix, high moisture content of about 91.8 ± 0.3%, carbohydrates (6.9 ± 1.2%), lipids (0.90 ± 0.17%), ashes (0.4 ± 0.0%), and not detectable protein. The evaluation of the scavenging activity of free radicals, such as 2,2-diphenyl-1-picryl-hydrazyl (DPPH) and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), of the flower extract was better than the results observed for other edible flowers (507.8 ± 2.7 µM TE and 783.9 ± 30.8 µM TE, respectively) as well as the total phenolic composition (TPC) value (568.8 ± 0.8 mg GAE/g). These flowers are rich in organic acids and phenolic compounds, mainly myricetin, and quercetin derivatives, kaempferol, and anthocyanins. The extract showed no cytotoxicity for the cell lineages used, suggesting that the extract has no directly harmful effects to cells. The important bioactive compound identified in this study makes this flower especially relevant in the healthy food area due to its nutraceutical potential without showing cytotoxicity.

Microstructured lipid microparticles containing anthocyanins: Production, characterization, storage, and resistance to the gastrointestinal tract.

Anthocyanins from grape peel extract have several biological properties and can act as a natural colorant and antioxidant agent. However, these compounds are susceptible to degradation by light, oxygen, temperature, and the gastrointestinal tract. Thus, this study produced microstructured lipid microparticles (MLMs) containing anthocyanins by the spray chilling technique and evaluated the particle stability. trans-free fully hydrogenated palm oil (FHPO) and palm oil (PO) were used as encapsulating materials in the ratios 90:10, 80:20, 70:30, 60:40, and 50:50, respectively. The concentration of grape peel extract was 40 % (w/w) in relation to the encapsulating materials. The microparticles were evaluated for thermal behavior by DSC, polymorphism, FTIR, size distribution and particle diameter, bulk density, tapped density, flow properties, morphology, phenolic compounds content, antioxidant capacity, and retention of anthocyanins. Furthermore, the storage stability of the microparticles was investigated at different temperatures (-18, 4, and 25 °C), and the anthocyanins retention capacity, kinetic parameters (half-life time and degradation constant rate), total color difference, and visual aspects were evaluated during 90 days of storage. The resistance of MLMs to the gastrointestinal tract was also evaluated. In general, higher FHPO concentrations increased the thermal resistance of the MLMs and both showed defined peaks of ß' and ß forms. The FTIR analysis showed that the MLMs preserved the original forms of their constituent materials even after atomization, with interactions between them. The increase in the PO concentration directly affected the increased mean particle diameter, agglomeration, and cohesiveness, as well as lower bulk density, tapped density, and flowability. The retention of anthocyanins in MLMs ranged from 81.5 to 61.3 % and was influenced by the particle size, with a better result observed for the treatment MLM_90:10. The same behavior was observed for the phenolic compounds content (1443.1-1247.2 mg GAE/100 g) and antioxidant capacity (1739.8-1660.6 mg TEAC/100 g). During the storage, MLMs made with FHPO to PO ratios of 80:20, 70:30, and 60:40 showed the highest stability for anthocyanin retention and color changes at the three temperatures (- 18 °C, 4 °C, and 25 °C). The gastrointestinal simulation in vitro revealed that all treatments were resistant to gastric phase and maintained a maximum and controlled release in the intestinal phase, demonstrating that FHPO together with PO are effective to protect anthocyanins during gastric digestion, and can improve the bioavailability of this compound in the human organism. Thus, the spray chilling technique may be a promising alternative for the production of anthocyanins-loaded microstructured lipid microparticles with functional properties for various technological applications.

Encapsulation of Bromelain in Combined Sodium Alginate and Amino Acid Carriers: Experimental Design of Simplex-Centroid Mixtures for Digestibility Evaluation.

Bromelain has potential as an analgesic, an anti-inflammatory, and in cancer treatments. Despite its therapeutic effects, this protein undergoes denaturation when administered orally. Microencapsulation processes have shown potential in protein protection and as controlled release systems. Thus, this paper aimed to develop encapsulating systems using sodium alginate as a carrier material and positively charged amino acids as stabilizing agents for the controlled release of bromelain in in vitro tests. The systems were produced from the experimental design of centroid simplex mixtures. Characterizations were performed by FTIR showing that bromelain was encapsulated in all systems. XRD analyses showed that the systems are semi-crystalline solids and through SEM analysis the morphology of the formed systems followed a pattern of rough microparticles. The application of statistical analysis showed that the systems presented behavior that can be evaluated by quadratic and special cubic models, with a p-value < 0.05. The interaction between amino acids and bromelain/alginate was evaluated, and free bromelain showed a reduction of 74.0% in protein content and 23.6% in enzymatic activity at the end of gastric digestion. Furthermore, a reduction of 91.6% of protein content and 65.9% of enzymatic activity was observed at the end of intestinal digestion. The Lis system showed better interaction due to the increased stability of bromelain in terms of the amount of proteins (above 63% until the end of the intestinal phase) and the enzymatic activity of 89.3%. Thus, this study proposes the development of pH-controlled release systems aiming at increasing the stability and bioavailability of bromelain in intestinal systems.

Edible flowers from Theobroma speciosum: Aqueous extract rich in antioxidant compounds.

Theobroma speciosum, known as "cacauí" in Brazil, is considered a prominent unconventional food plant. The objective of this work was to evaluate the chemical profiles, antioxidant capacity and minerals of the aqueous extract and fractions from its flowers. The identified compounds were sugars, organic acids and phenolics compounds such as citric, malic and protocatechuic acids, quercetin, quercetin pentoside and quercetin-3-O-glucoside. The extract was rich in phenolic compounds (640 mg GAE g-1). Furthermore, fractions also presented phenolic compounds from 170.7 to 560.7 mg GAE g-1 (mainly protocatechuic acid, quercetin and derivatives), which influenced on the high antioxidant capacity in DPPH, ABTS, FRAP and co-oxidation ß-carotene/linolenic acid assays. Flowers presented potassium (115 ± 2 µg mL-1), magnesium (18.4 ± 0.2 µg mL-1), phosphorus (7.0 ± 0.0 µg mL-1) and calcium (3.1 ± 0.1 µg mL-1). Moreover, the flowers aqueous extract represents a new promising food source rich in antioxidant compounds.

Ariá (Goeppertia allouia) Brazilian Amazon tuber as a non-conventional starch source for foods.

Ariá (Goeppertia allouia) is a tuber from the arrowroot's family widely found in the Brazilian Amazon. The tuber has a flavor similar to corn, besides high retrogradation when cooked, differing from other commercial starches. To enhance its added value, the Ariá starch was extracted to evaluate its potential as a food ingredient. The Ariá starch was compared to the commercially available corn and potato starches regarding their physicochemical, thermal, structural, and rheological properties based on the Duncan's test (p-value <0.05). The Ariá starch presented high amylose content (~38% w/w). Furthermore, the X-ray diffraction pattern confirmed its Type-C crystalline structure. The rheological properties showed that the starch gels presented high hardness and retrogradation as other studied starches. Ariá has great potential as a source of starch with low digestibility, increasing the satiety of food products.

Dielectric barrier atmospheric cold plasma applied on camu-camu juice processing: Effect of the excitation frequency.

The aim of this paper was to evaluate the effect of cold plasma excitation frequency on camu-camu juice processing. Different levels of frequency (200, 420, 583, 698 and 960 Hz) were applied on camu-camu juice to measure the contents of ascorbic acid and anthocyanins, as well as to evaluate the antioxidant compounds (DPPH, ABTS, FRAP and phenolic compounds), peroxidase and polyphenol oxidase enzymatic activity and color. Furthermore, the juice bioaccessibility was evaluated after simulated digestion. The ascorbic acid concentration was increased when higher excitation frequencies were employed, increasing their bioavailability. Anthocyanins, peroxidase and polyphenol oxidase presented considerable degradation with increasing the plasma excitation frequency. For this reason, the juice processing proposed herein represents an alternative to enhance its nutritional quality. Moreover, the use of cold plasma reduced the activity concentration of endogenous enzymes, presenting considerable degradation for higher excitation frequency.

Stability of lime essential oil microparticles produced with protein-carbohydrate blends.

The objective of this work was to analyze the influence of maltodextrin equivalent dextrose on the lime essential oil reconstitution, storage, release and protection properties. Four treatments were evaluated: whey protein concentrate (WPC), and blends of maltodextrin with dextrose equivalents of 5 (WM5), 10 (WM10) and 20 (WM20). The reconstitution and storage properties of the microparticles (solubility, wettability and density), water kinetics adsorption, sorption isotherms, thermogravimetric properties, controlled release and degradation kinetics of encapsulated lime essential oil were studied to measure the quality of the encapsulated materials. The results of the study indicated that the DE degree influences the characteristics of reconstitution, storage, controlled release and degradation characteristics of encapsulated bioactive compounds. The increase in dextrose equivalent improves microparticle solubility, wettability and density, mainly due to the size of the maltodextrin molecules. The adsorption kinetics and sorption isotherm curves confirmed the increase in the hygroscopicity of maltodextrins with higher degrees of polymerization. The size of the maltodextrin chains influenced the release and protection of the encapsulated lime essential oil. Finally, the maltodextrin polymerization degree can be considered a parameter that will influence the physicochemical properties of microencapsulated food.