Non-thermal technologies for the conservation of açai pulp and derived products: A comprehensive review.

Açai (Euterpe oleracea) is one of the main sustainable extractive crops in the Amazon region, widely consumed by the local population and a significant export product. This review presents the current knowledge regarding nonthermal technologies employed in açai processing. This review aims to discuss and compare the main results attained by the application of HPP, ultrasound, ozone, UV light, cold plasma, and pulsed electric field on microbial inactivation, enzymatic inhibition, and the content of anthocyanin and other bioactive compounds after açai pulp processing. The discussion compares these technologies with pasteurization, the current main technology applied to açai sanitization. This review shows that there are still many gaps to be filled concerning açai processing in thermal and non-thermal technologies. Data analysis allowed the conclusion that pasteurization and HPP are, up to now, the only technologies that enable a 5-log CFU reduction of yeasts, molds, and some bacteria in açai. However, no study has reported the inactivation of Trypanosoma cruzi, which is the major gap found in current knowledge. Other technologies, such as pulsed electric field, cold plasma, and ultrasound, require further development and process intensification studies to be as successful as HPP and pasteurization.

Ultrasound-assisted extraction using ethanol efficiently extracted carotenoids from peels of peach palm fruits (Bactris gasipaes Kunth) without altering qualitative carotenoid profile.

Peach palm (Bactris gasipaes Kunth) is an amazonian fruit in which its peel has been appointed as a carotenoid-rich byproduct with biological properties. For analytical purposes, carotenoids are frequently extracted by non-green (use of toxic organic solvents) and time-consuming methods, which can affect the quality (carotenoid profile) and safety of extracts for direct food applications. We investigated herein the effect of different extraction methods on the individual carotenoid profile of extracts of peach palm peels by HPLC-DAD. Carotenoid extractions were carried out by maceration in mortar with pestle (with acetone or ethanol), magnetic stirring, shaker and ultrasound-assisted extraction (UAE) using ethanol. UAE provided the highest carotenoid contents (67 mg/100 g), followed by maceration with acetone and ethanol (63 and 52 mg/100 g, respectively), while the lowest contents were observed for the magnetic stirring and shaker extractions (44 mg/100 g), being (all-E)-ß-carotene and a Z-isomer of γ-carotene accounted 54-73% of the carotenoid composition. HPLC-DAD data showed the same carotenoid profile regardless the extraction method, yet the percentage of Z-isomers of ß-carotene was higher for the shaking (18%), UAE (17%) and magnetic stirring (15%) than for both maceration methods (7 and 8%, with acetone and ethanol, respectively). Thus, the tested extraction methods affected the total carotenoid contents, whereas the chromatographic profile did not change. Furthermore, a carotenoid-rich extract was effectively obtained by using ethanol associated with ultrasound technique (less time-consuming) instead of toxic and non-safe solvents.

Encapsulation of bioactive compounds extracted from plants of genus Hibiscus: A review of selected techniques and applications.

The genus Hibiscus includes more than 250 species, and many studies showed that these plants contain bioactive compounds with technological potential to be used in the development of functional foods. However, the instability of these compounds during typical food processing conditions, such as exposure to high temperatures, pH changes and presence of light and oxygen have stimulated the use of encapsulation techniques to increase their stability and applicability. Among the existing Hibiscus species, only H. sabdariffa, H. cannabinus, and H. acetosella have been investigated in encapsulation studies, being spray drying the most common method approached. Considering the high technological potential offered by the incorporation of encapsulated bioactive compounds from plants of the genus Hibiscus in food formulations, this review discusses key information of selected encapsulation techniques, which represents promising alternatives to increase food systems' stability and stimulate the design of new functional foods. Relevant gaps in the literature were also noticed, mainly the lack of systematic studies regarding the composition of bioactive compounds after encapsulation, instead of total determinations, and biological activities in different analytical systems, such as antioxidant, antimicrobial and anti-inflammatory properties as well as bioaccessibility and bioavailability.

Antrocaryon amazonicum: An unexploited Amazonian fruit with high potential of scavenging reactive oxygen and nitrogen species.

Antrocaryon amazonicum fruits are unexploited sources of bioactive compounds found in the Amazonia region of Brazil. In this study, for the first time, the carotenoid and phenolic compound profiles of the pulp and peel of A. amazonicum fruits, from two varieties at two harvest periods, were determined by LC-MS. Additionally, the potential of the peel and pulp extracts to scavenge physiologically relevant reactive oxygen species (ROS) and reactive nitrogen species (RNS) was assessed. The major carotenoids in both parts of the fruits were lutein, accounting for ≈42% of the identified carotenoids in the peel and ≈25% in the pulp, whereas catechin and hydroxybenzoic acid derivatives were the major phenolics in both parts. The peel extract, which presented the highest bioactive compound contents, was more efficient to scavenge ROS than the pulp. The peel extract showed high scavenging efficiency (IC50 ) for singlet oxygen (1 O2 ; 16 µg/ml), hypochlorous acid (HOCl; 20 µg/ml), peroxynitrite (ONOO- ; 38 µg/ml), and superoxide radical (O2 •- ; 47 µg/ml), whereas the pulp extract exhibited high efficiency for ONOO- (13 µg/ml), followed by HOCl (30 µg/ml), ¹O2 (76 µg/ml), and less efficient for O2 •- (44 µg/ml). Therefore, A. amazonicum fruits can be seen as an expressive source of bioactive compounds with high antioxidant potential to be further investigated to inhibit or delay oxidative processes both in food and physiological systems triggered by ROS and RNS. PRACTICAL APPLICATION: Bioactive compound extracts of Antrocaryon amazonicum fruits have high potential to be exploited for inhibiting or delaying oxidative processes and increase food stability.

Peach palm flour: production, hygroscopic behaviour and application in cookies.

In this work, two types of flour from peach palm fruits (Bactris gasipaes) were prepared to be used to produce cookies: one with the whole fruit (pulp + peel) and another one with only the pulp. Analyses of proximate composition, physicochemical and hygroscopic behaviour were carried out in both flour, as well as sensory analysis of the produced cookies. Both the types of flour did not differ statistically in total lipids, total carbohydrates and ashes (p > 0.05). Among the mathematical models tested for the prediction of the hygroscopic behaviour of both flour, Halsey model showed the best fit to the experimental data (R2 = 0.99 and P<10%). The cookies produced with both types of peach palm flour presented low moisture (4.9-6.2%), high lipid content (25.56-26.37%) and total carbohydrates (59.10-61.84%), resulting in a product with high total energetic value (501.8-502.8 kcal/100 g). Based on the results of acceptance test, both cookie formulations presented good sensory acceptance (>70%). The purchase intention inquiry showed that the cookie prepared with the whole fruit flour presented the highest percentage of purchase intention (85%), which demonstrate that the use of peach palm peels in the development of new food products represent an excellent alternative for the use of by-products.

Profile of phenolic compounds and carotenoids of Arrabidaea chica leaves and the in vitro singlet oxygen quenching capacity of their hydrophilic extract.

Arrabidaea chica (Brazilian name = pariri) is a plant species that belongs to the Bignoniaceae family, occurring in tropical America and widespread in the Amazonian region of Brazil. In this study, the phenolic compound and carotenoid profiles of A. chica leaves were determined by HPLC-DAD-MS. Scutellarin was identified as the main phenolic compound (15,147.22 µg/g, dry basis, d.b.) and lutein (204.28 µg/g, d.b.), ß-carotene (129.5 µg/g, d.b.) and α-carotene (79.86 µg/g, d.b.) as the major carotenoids. Moreover, A. chica leaves presented 152.7 µg/g of ascorbic acid (fresh weight). For the first time, the carotenoid profile and ascorbic acid contents were reported for A. chica leaves. Regarding the antioxidant capacity, A. chica extract was able to scavenge ABTS radical (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid)), and for the first time, the protective effect against singlet oxygen (1O2) was reported. The A. chica extract was efficient as ABTS radical scavenger (86.81 µM Trolox/g of fresh leaves) and inhibited the degradation of tryptophan by 1O2 in a concentration-dependent manner with an IC50 at 177 µg/mL. Thus, A. chica leaves can be exploited as a promising source of bioactive compounds that may be useful to human health or food systems against oxidative damage.

Influence of spontaneous fermentation of manipueira on bioactive amine and carotenoid profiles during tucupi production.

Tucupi is a kind of broth that is common to the Amazonian region of Brazil, which is produced after the spontaneous fermentation and boiling of manipueira, a liquid by-product extracted from cassava roots during cassava flour production. The bioactive amines formation and their alterations during tucupi processing were investigated for the first time. In addition, the physicochemical changes, instrumental color parameters and carotenoid profile were monitored during tucupi production. Regarding the changes on the profile of carotenoids, all-trans-ß-carotene was the major carotenoid, followed by its 9- and 13-cis isomers, and this profile was not altered throughout the process. Spermidine (polyamine), putrescine, tyramine and histamine (biogenic amines) were the bioactive amines identified during the tucupi production process, but at low levels (0.76-7.24 mg/L). Principal Component Analysis suggested three distinct stages during tucupi production: the first stage was characterized by the manipueira up to 12 h of fermentation with the highest values of pH, total and reducing sugars, and total starch; the second stage refers to the end of the fermentation process (16 to 24 h), in which biogenic amines (histamine and tyramine) were produced; and the third stage was characterized by the final product (tucupi), with the highest values of total acidity, soluble solids, polyamines and tyramine. Therefore, the results suggest the need of an accurate control of the fermentation of the manipueira to avoid or minimize the formation of biogenic amines.

Peels of tucumã (Astrocaryum vulgare) and peach palm (Bactris gasipaes) are by-products classified as very high carotenoid sources.

Tucumã (Astrocaryum vulgare) and peach palm (Bactris gasipaes) are Amazonian fruits with high potential to be used as source of carotenoids due to the remarkable yellow-orange colour of their pulp and peel. In this study, for the first time, both the extraction of carotenoids from the peel of tucumã and peach palm fruits and their carotenoid profile were investigated. The carotenoid contents of the peel of both fruits were higher than those found in the pulp. The highest yield of carotenoids from both fruit peels were obtained at the solid-liquid ratio of 1:7 (w/v), 80 min of shaking and by adding 30% of ethyl acetate in acetone, being ß-carotene the major carotenoid (7.8 and 7.3 mg/100 g for tucumã and peach palm, respectively), followed by γ-carotene and δ-carotene. Thus, peels of tucumã and peach palm fruits were classified as very high carotenoid sources to be used by any potential interested industry.

Phenolic compounds are highly correlated to the antioxidant capacity of genotypes of Oenocarpus distichus Mart. fruits.

This research aimed to evaluate 32 genotypes of Oenocarpus distichus fruits regarding the contents of total phenolic compounds, flavonoids, flavanols, monomeric anthocyanins, antioxidant capacity (ABTS and DPPH assays), and the phenolic compound profiles of the five genotypes that presented the highest yields of bioactive compounds. The genotypes were harvested in three different locations in Pará State, Northern Brazil, (Belém, São João do Araguaia and Marabá). Among the 32 genotypes, the highest bioactive compound contents and antioxidant capacity were found for three genotypes harvested in Belém (B-3, B-7 and B-8) and two harvested in São João do Araguaia (SJ-1 and SJ-4), and the total phenolic compounds varied from 131.97 to 363.01 mg gallic acid equivalent/100 g, total flavonoids from 24.23 to 38.19 mg quercetin equivalent/100 g, total flavanols from 72.29 to 259.18 mg catechin equivalent/100 g, and monomeric anthocyanins from 21.31 to 67.76 mg cyanidin 3-rutinoside/100 g. The main phenolic compounds tentatively identified in the five selected genotypes were cyanidin 3-O-rutinoside (48.47 to 196.51 µg/g), which could be identified and quantified as the major phenolic compound in Oenocarpus distichus fruits, for the first time, followed by chlorogenic acid (0.71 to 64.56 µg/g) and rutin (13.98 to 56.76 µg/g).

Anthocyanins of Jambolão (Syzygium cumini): Extraction and pH-Dependent Color Changes.

Jambolão fruits are promising sources of anthocyanins, and in this study, the jambolão fruit from the Brazilian Amazonian region was characterized and the efficiency of six ethanol-based solutions to extract anthocyanins was determined. Moreover, the color changes of anthocyanin extracts, as influenced by different pH conditions (pH from 1.0 to 8.0), were evaluated. The fruits exhibited high contents of total anthocyanins (296 mg/100 g) and the CIELAB parameters characterized jambolão as a purple-red colored fruit (a* = 20.30, b* = -4.17, and hab∘= 348.39). Among the six different ethanol-based solutions, ethanol 95% with 1% of HCl (v/v) was the most efficient solution to extract anthocyanins from jambolão fruits. Furthermore, the CIELAB parameters were characterized as useful tool to monitor the color changes of anthocyanins of jambolão over the tested pH range. Therefore, jambolão fruits from Amazonian region have technological potential for the application by food, pharmaceutical, and cosmetic industries. PRACTICAL APPLICATION: Jambolão fruits are great source of anthocyanins and the incorporation of these natural pigments as food colorants is not only valuable to improve overall appearance, but it is also beneficial to human health. The production of natural extracts with high levels of anthocyanins from jambolão can be considered a very useful approach to the food, pharmaceutical and cosmetic industries.

Bioactive amines and phenolic compounds in cocoa beans are affected by fermentation.

Cocoa is the target of increased scientific research as it is one of the richest source of bioactive compounds. The formation of bioactive amines and their changes in cocoa beans during seven days of traditional fermentation was investigated for the first time. In addition, total phenolic compounds, anthocyanins contents and the scavenging capacity against ABTS radical were determined to monitor the fermentation process. Only two biogenic amines (tryptamine and tyramine) and two polyamines (spermidine and spermine) were detected in cocoa beans during fermentation. Fermentation was characterized by three stages: i) high levels of tryptamine, phenolics, and scavenging capacity; ii) high contents of spermine, total biogenic amines and total polyamines; and iii) the highest spermidine levels and total acidity, but the lowest total phenolic compounds and anthocyanins contents. The scavenging capacity of cocoa beans during fermentation correlated with total phenolic compounds and anthocyanins contents.