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A total of 19 Brazilian frozen pulps from the following fruits: açai (Euterpe oleracea), blackberry (Rubus sp.), cajá (Spondias mombin), cashew (Anacardium occidentale), cocoa (Theobroma cacao), coconut (Cocos nucifera), grape (Vitis sp.), graviola (Annona muricata), guava (Psidium guajava), papaya (Carica papaya), peach (Prunus persica), pineapple (Ananas comosus), pineapple and mint (A. comosus and Mentha spicata), red fruits (Rubus sp. and Fragaria sp.), seriguela (Spondias purpurea), strawberry (Fragaria sp.), tamarind (Tamarindus indica), umbu (Spondias tuberosa), and yellow passion fruit (Passiflora edulis) were analyzed in terms of chromaticity, phenolic compounds, carotenoids, and in vitro antioxidant activity using ferric reducing antioxidant power (FRAP) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) assays. Data were processed using principal component analysis (PCA) and hierarchical cluster analysis (HCA). Antioxidant capacity was measured by DPPH and FRAP assays, which showed significant (P < 0.01) correlation with total phenolic compounds (r = 0.88 and 0.70, respectively), total flavonoids (r = 0.63 and 0.81, respectively), and total monomeric anthocyanins (r = 0.59 and 0.73, respectively). PCA explained 74.82% of total variance of data, and the separation into 3 groups in a scatter plot was verified. Three clusters also suggested by HCA, corroborated with PCA, in which cluster 3 was formed by strawberry, red fruits, blackberry, açaí, and grape pulps. This cluster showed the highest contents of total phenolic compounds, total flavonoids, and antioxidant activity.

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The aim of this study was to evaluate the effects of gamma radiation on the phenolic compounds and antioxidant activity of apple pomace flour (0, 1 and 2 kGy dose at times of 0, 3, 6 and 9 months) during storage using multivariate techniques. The a* and h°colour attributes at a dose of 1 kGy, and the phenolic compound phloridzin showed constant levels during the experiment. The dose of 1 kGy at time 0 provides better results for antioxidant activity, total phenolic compounds and some individual compounds. Chlorogenic acid and its class of hydroxycinnamic acids increased proportionally with time in the irradiated samples. The chemometric approach made it possible to observe the influence of irradiation and storage time on the samples of apple pomace flour. The effect of irradiation on the phenolic compounds was related to the intensity and the characteristics of each individual compound. Industrial relevance: Irradiation has been shown to be an economically viable alternative for the treatment of foods; it has several advantages compared to traditional processing methods and can be applied independently or combined with existing techniques such as dehydration. Thus, this combination of treatments, as well as increasing the shelf life of apple pomace also increases the concentrations of nutrients and can be applied in the pharmaceutical, cosmetics and food industries. This advantage can translate into economic advantages, with added values in various applications and help to partially reduce negative impacts on the environment.

The effects of different doses of gamma radiation on the thermoanalytical, structural and pasting properties of black rice (Oryza sativa L.) flour were studied using thermogravimetry and derivative thermogravimetry (TG-DTG), differential scanning calorimetry, X-ray diffraction (XRD), field emission gun-scanning electron microscopy (FEG-SEM) and pasting properties (RVA) analysis. The thermogravimetric curves showed four mass losses. A small displacement was observed for the second loss, which occurred for the irradiated flours, compared to the control sample. The irradiated samples showed a slight decrease in the thermal parameters: initial temperature (T o), peak temperature (T p) and gelatinisation enthalpy (4H). All the black rice flours exhibited A-type crystallinity pattern, and the gamma radiation did not change the XRD patterns or the degree of crystallinity. The microimages obtained using FEG-SEM showed a composite of organic and heterogeneous material; after gamma radiation, some changes occurred, such as cracks, pores and smaller fragments. The pasting properties decreased significantly with irradiation. The decrease in setback and breakdown viscosity after irradiation suggested an indication that it may be possible to improve the quality of food based on black rice flours. Gamma radiation can be a useful tool to modify rice flours in order to suit various functionalities and to help meet the growing demands of the food industry.