Pressurized liquid extraction (PLE) is a clean and environmentally friendly alternative for the recovery of bioactive compounds from fruit by-products. Herein we focused on PLE for the extraction of bioactive compounds from pomegranate peel using a combination of pressurized water and ethanol. The main aim was to determine the optimal PLE conditions, i.e., ethanol percentage and process temperature, to obtain a pomegranate peel extract (PPE) with maximum total phenolic content (TPC), punicalagin content, and antimicrobial activity (AMA). The experimental design was conducted using a central composite design with axial points. Response surface methodology was applied to optimize the response variables using the desirability function. Multiple response optimization indicated a process temperature of 200 °C and ethanol of 77% as optimal conditions. The TPC and the punicalagin content of PPE-PLE obtained under optimal conditions were 164.3 ± 10.7 mg GAE/g DW and 17 ± 3.6 mg/g DW, respectively. Our findings support the efficacy of PLE on TPC recovery but not in punicalagin recovery. The AMA against S. aureus was 14 mm. The efficacy of PPE-PLE in food applications must continue to be studied in order to achieve adequate information on its potential for developing new food additives.
Purple flesh cultivated potato (PP) is a foodstuff scarcely cultivated in the world but with high potential because of its anthocyanin content. Moreover, it has been little explored as a source of anthocyanins (AT) for further applications in formulated food products. The main goal of this research was to study the effect of maltodextrin (MD) and spray drying conditions on the encapsulation efficiency (EE) and bioaccesibility of AT from purple flesh cultivated potato extract (PPE). The anthocyanin-rich extract was obtained from PP and microencapsulated by spray-drying, using MD as the encapsulating agent. A statistical optimization approach was used to obtain optimal microencapsulation conditions. The PPE microparticles obtained under optimal conditions showed 86% of EE. The protector effect of microencapsulation on AT was observed to be stable during storage and in vitro digestion. The AT degradation rate constant was significantly lower for the PPE-MD than for the PPE. The assessed bioaccesibility of AT from the PPE-MD was 20% higher than that of the PPE, which could be explained by the protective effect of encapsulation against environmental conditions. In conclusion, microencapsulation is an effective strategy to protect AT from PP, suggesting that AT may be an alternative as a stable colorant for use in the food industry.
The entomopathogenic fungus Beauveria pseudobassiana strain RGM 2184 can reach a maximum efficacy of 80% against the quarantine pest Lobesia botrana in field assays. In this study, the RGM 2184 genome was sequenced, and genome mining analyses were performed to predict the factors involved in its insecticidal activity. Additionally, the metabolic profiling of the RMG 2184 culture’s supernatants was analyzed by mass spectrometry, and the insecticidal activity from one of these extracts was evaluated in Galleria mellonella larvae. The genome analysis resulted in 114 genes encoding for extracellular enzymes, four biosynthetic gene clusters reported as producers of insecticidal and bactericidal factors (oosporein, beauvericin, desmethylbassianin, and beauveriolide), 20 toxins, and at least 40 undescribed potential biocontrol factors (polyketides and nonribosomal peptides). Comparative genomic analysis revealed that 65–95% of these genes are Beauveria genus-specific. Metabolic profiling of supernatant extracts from RGM 2184 cultures exhibited secondary metabolites such as beauveriolide, oosporein, inflatin C, and bassiatin. However, a number of detected metabolites still remain undescribed. The metabolite extract caused 79% mortality of Galleria mellonella larvae at 28 days. The results of this research lay the groundwork for the study of new insecticidal molecules.
During ripening, ‘Hass’ avocado skin changes from green to purple/black. Low-temperature storage with a controlled atmosphere (CA) is the most widely used method for avocado storage; however, few studies have simulated this technology and considered the days of regular air (RA) storage prior to CA storage. Herein, the effect of delaying the storage of ‘Hass’ avocado (>30% dry matter) in a CA was examined. Long-term storage conditions (5 °C for 50 days) corresponded to (i) regular air storage (RA), (ii) CA (4 kPa O2 and 6 kPa CO2) and (iii) 10 days in RA + 40 days in a CA and (iv) 20 days in RA + 30 days in a CA. Evaluations were performed during storage and at the ready-to-eat (RTE) stage. Skin color remained unchanged during storage, but at the RTE stage, more color development was observed for fruits stored under CA conditions, as these fruits were purple/black (>50%). At the RTE stage, the anthocyanin content increased, and compared to fruit under RA, fruit under a CA contained a five-fold greater content. A 20-day delay between harvest and CA storage increased the fruit softening rate and skin color development after cold storage, reducing the effectiveness of CA as a postharvest technology for extending storage life.
The black carrot (Daucus carota L.) is a source of anthocyanins (AT), especially acylated forms, valued for their color and antioxidant properties, which are linked to the prevention of diseases caused by oxidative stress. However, their low stability to pH and temperature limits their application. This work aimed to evaluate the effect of spray-drying microencapsulation of black carrot juice (BCJ) on the stability and bioaccessibility of AT. Spray-drying (SD) was used as an encapsulation technique with conventional (two-nozzle) and three-nozzle, and maltodextrin (MD) was used as the encapsulating agent; sodium alginate (SA) was used as the outer layer. The SD optimal conditions were 150 °C and a BCJ:MD ratio of 1:2. Two systems were obtained: BCJ-MD and (BCJ-MD)-SA, both with encapsulation efficiencies above ~90%. During storage for 198 days at 60 °C, both systems significantly reduced the degradation constant compared to free juice, following pseudo-first-order kinetics. However, a critical finding was that in vitro bioaccessibility was significantly higher in the conventional BCJ-MD (~88%) compared to the BCJ-MD-SA system (~44%). These results suggest that maltodextrin alone is a more effective strategy for maximizing the in vitro bioaccessibility of black carrot anthocyanins, thereby providing a stable, highly bioaccessible healthy ingredient for the food industry.
Unpasteurized fruit juices are prone to microbiological spoilage by bacteria, yeasts, and molds, creating a need for natural preservatives to extend shelf life without compromising quality. Pomegranate peel extract (PPE) exhibits antimicrobial activity primarily against pathogenic microorganisms; however, its effect on spoilage microorganisms in fruit juices has not been previously studied. This work aimed to compare the microbiological stability of unpasteurized apple juice when adding non-encapsulated PPE or PPE microparticles produced by spray drying with inulin (PPE-IN), inulin combined with sodium alginate (PPE-(IN+SA)), or inulin combined with carrageenan (PPE-(IN+CR)) as encapsulating agents. All microparticle systems showed high encapsulation efficiency (>90%), with PPE-IN reaching 94.08%. For the stability study, PPE microparticles (0.018 to 0.023 g/mL) or PPE (0.009 g/mL) were added to 70 mL of juice and stored at 4 °C for 9 days. MAB, molds, and yeasts were then quantified. At 3, 6, and 9 days, the J+PPE-(IN+CR) treatment showed the lowest MAB, molds, and yeast counts in relation to the non-encapsulated PPE and the other microparticle system. These results indicate that PPE-(IN+CR) microparticles provide superior microbiological stability of apple juice up to day 9, suggesting that the combination of encapsulating agents (IN+CR) could control the release of PPE into the juice.