Bordo grape skin extract was microencapsulated by spray-drying and freeze-drying, using gum arabic (GA), partially hydrolyzed guar gum (PHGG), and polydextrose (PD) as encapsulating agents. Total phenolics and total monomeric anthocyanin, antioxidant activity, color, moisture, water activity (aw), solubility, hygroscopicity, glass transition temperature (Tg), particle size, and microstructure of the powders were evaluated. The retention of phenolics and anthocyanins ranged from 81.4% to 95.3%, and 80.8% to 99.6%, respectively, while the retention of antioxidant activity ranged from 45.4% to 83.7%. Treatments subjected to spray-drying had lower moisture, aw, and particle size, and greater solubility, while the freeze-dried samples were less hygroscopic. Tg values ranged from 10.1 to 52.2°C, and the highest values corresponded to the spray-dried microparticles. The spray-dried particles had spherical shape, while the freeze-dried powders showed irregular structures. The spray drying technique and the use of 5% PHGG and 5% PD has proven to be the best treatment.

This study aimed at microencapsulating palm oil, containing high carotenoid content, with chitosan/xanthan and chitosan/pectin, using the complex coacervation method, followed by atomization and lyophilization. The DSC technique was used to confirm the encapsulation. The atomized microparticles had spherical shape and irregular size, and the lyophilized microparticles had irregular shape and size. Lyophilization resulted in lower carotenoids losses, and higher yield and encapsulation efficiency. In addition, the release profile in both water and gastrointestinal fluid was satisfactory. Prior to their application in food, a greater percentage of carotenoids was released in the fluid that simulates gastrointestinal conditions; however, the compounds were degraded after their release. In this case, the chitosan/pectin microparticles showed the best release profile. After processing, the release was lower and the released compounds were not degraded. Thus, the chitosan/xanthan microparticles showed the best potential for practical application, particularly, in yogurt preparation.

The stability of microparticles of Bordo grape skin aqueous extract, produced by spray-drying and freeze-drying using polydextrose (5%) and partially hydrolyzed guar gum (5%), was evaluated under accelerated conditions (75 and 90% relative humidity, at 35, 45, and 55°C for 35days) and simulated gastrointestinal digestion. The temperature had a significant effect on the reduction of phenolics content, with retentions varying from 82.5 to 93.5%. The retention of total monomer anthocyanins were in the range of 3.9-42.3%. The antioxidant activity had a final retention of 38.5-59.5%. In the simulated gastrointestinal digestion, a maximum release was observed for the phenolic compounds in the intestinal phase (90.6% for the spray-dried powder and 94.9% for the freeze-dried powder), as well as the antioxidant activity (69.4% for the spray-dried powder and 67.8% for the freeze-dried powder). However, a reduction of monomeric anthocyanins was observed in the intestinal phase.

The effect of irradiation through UV-C on the content of phenolic compounds, antioxidant activity, color, and texture profile was evaluated in Bordô variety grapes. Grapes were subjected to stress by irradiation at time of 0.5, 1.0, 4.0, 10 and 30 min that correspond at doses of 0.1, 0.3, 1.0, 2.4, and 7.2 kJ m -2 , respectively. The total phenolic and anthocyanins content, antioxidant activity, color and texture of the grapes were evaluated after storage at 22 ºC for 24 and 48 h. In general, samples irradiated did not show an increase in total phenolic content, anthocyanin compounds and antioxidant activity. Hue and Chroma values indicated that the color of grapes did not change when irradiated. Texture profile analysis suggested that UV-C treatment delayed grapes softening.

Gum Arabic (GA), β‐cyclodextrin (β‐CD), and hydroxypropyl‐β‐cyclodextrin were used in different proportions to microencapsulate polyphenols obtained by aqueous extraction from a grape skin. Phenol contents of the microcapsules were evaluated for anthocyanins, flavonoids and total flavanols, antioxidant activity, color, moisture, water activity (Aw), solubility, hygroscopicity, and glass transition temperature (Tg). The microcapsules prepared with either 5% GA or a mixture of 3% GA and 2% β‐CD had the highest retention of phenolic (78.9 and 67.5%, respectively), anthocyanins (35.3 and 29%, respectively) and antioxidant activity greater than 50% measured by the DPPH and CUPRAC methods. Treatment with 3% GA and 2% β‐CD showed the highest retention of flavonoids (67.2%) and total flavanols (51.1%), as well as physical properties suitable for this type of product, such as Aw of 0.175, solubility greater than 90%, hygroscopicity of 17.3%, and Tg of 32.8°C, which may contribute to a greater stability of the powder. Practical applications Grape processing by‐products have a great feasible commercial, and this is due at high concentrations of phenolic compounds in grape skin. It was possible to obtain inclusion complexes powder of phenolic compounds from grape skin, using cyclodextrin and its derivates in mixture with Arabic gum as carriers. This way, the stability of bioactive compounds may be improved during food processing, storage and pass through the gastrointestinal tract. In addition, it is possible to enhance solubility of phenolics compounds in aqueous dispersions. Powders obtained have antioxidant properties and potential prebiotic activity.

Experimental data obtained from the literature concerning the growth rate of 35 different enterobacteria and acidification of the media using various carbohydrates as the substrates (glucose and the fructooligosaccharides Profeed P95, Raftilose P95 and Raftiline LS), were submitted to a multivariate statistical analysis of the principal components and clusters. The objective was to evaluate the degree of correlation between the substrates and the microorganisms, grouping them according to their affinities. When the growth rates of the enterobacteria were evaluated, strong correlation was observed between the substrates composed of short chain fructose oligosaccharides (Profeed P95 and Raftilose P95). The microorganisms could be separated into four groups, similarities being found between enterobacteria of the same genus and/or species. With respect to acidification of the medium, strong correlation was observed between glucose and Profeed, which have a greater percentage of glucose units in the chain. However, it was found poor correlation among microorganisms from the same genus and/or species, as well as between the enterobacteria species and fermentation of the carbohydrates.