The aim of this study was to investigate the potential of retrieving polyphenolic antioxidants directly from wet pomegranate marcs: the fresh by-products obtained after pomegranate juice processing. These by-products mainly consist of internal membranes (endocarp) and aril residues. Even if they are still edible, they are usually discharged during juice production and, thus, they represent a great challenge in an eco-sustainable industrial context. Green technologies, such as ultrasound assisted extraction (UAE) and microwave assisted extraction (MAE), have been employed to convert these organic residues into recycled products with high added value. UAE and MAE were used both in parallel and in series in order to make a comparison and to ensure exhaustive extractions, respectively. Water, as an environmentally friendly extraction solvent, has been employed. The results were compared with those ones coming from a conventional extraction. The most promising extract, in terms of total polyphenol yield and radical scavenging activity, has been tested both as a potential natural additive and as a functional ingredient after its incorporation in a real food model and in a real cosmetic matrix, respectively. This study represents a proposal to the agro-alimentary sector given the general need of environmental “responsible care”.

Ellagic acid (EA) is a bioactive natural polyphenol with antioxidant and several other beneficial properties, but unfortunately it cannot be exploited for in vivo therapeutic applications because of its poor water solubility and accordingly low bioavailability. Aiming to increase EA solubility, an EA solid microdispersion was realized by employing only water and low methoxylated pectin as a food compatible excipient by applying spray drying technology. It showed a 22% (w/w) Drug Loading (DL), a 30 times improved water solubility and remarkable radical scavenging activity. Subsequently, adopting non-PAMAM hydrophilic and amphiphilic dendrimers as nanocontainers, two EA nanodispersions were achieved (60–70 nm) with 46 and 53% (w/w) DL, water solubility 300 to 1000 times higher than that of free EA and good antioxidant capability. In both cases, toxic agents such as castor oil, Tween 80 or the extensively used but not so safe PEG400 were avoided and no previously used carriers, including β-cyclodextrins, were adopted. The prepared micro- and nanodispersions showed water solubility never obtained before and represent non-toxic EA reservoirs suitable for food and biomedical applications.

FINNOVER is an EU Interreg-Alcotra project that aims to bring new perspectives to floriculture enterprises by recovering useful bioproducts from the waste produced during processing of several aromatic species. In this study, a new operation strategy to recover lavender (Lavandula angustifolia Mill.) solid by-products remaining after the extraction of the essential oil was developed. Pulsed ultrasound-assisted extraction was employed as a sustainable and eco-compatible technology to extract, in a very short time (10 min), this agricultural waste using a food-grade solvent (a mixture of ethanol/water). All the extracts obtained from both flower and leaf waste and flower-only residues, exhibit a promising total phenolic content (38–40 mg gallic acid/g of dry waste), radical scavenging activity (107–110 mg Trolox/g of dry waste) and total flavonoid content (0.11–0.13 mg quercetin/g of dry waste). Moreover, the chromatographic analysis of these extracts has shown that this overlooked agriculture waste can represent a valuable source of multifunctional compounds. Particularly, they exhibit a content of polyphenols and flavonoids up to 200 times higher than the corresponding leachate, and they are a valuable source of gentisic acid (1.4–13 mg/g dry waste) representing a new low-cost ingredient usable in different fields (i.e., cosmetic).

The aim of the study is to evaluate the anti-tyrosinase activity of different aqueous extracts obtained from pomegranate juice processing by-products. External pomegranate peels of two certified cultivars (Akko and Wonderful), were extracted using only water as the extraction solvent. A traditional decoction and a pulsed ultrasound-assisted extraction (PUAE), both 10 min long, were performed and compared. All the aqueous extracts proved to be rich in bioactive compounds. In particular, the total phenolic content (TPC) ranged from 148 to 237 mg gallic acid equivalent (GAE)/g of dried peels (DW), the radical-scavenging ability (RSA) ranged from 307 to 472 mg ascorbic acid equivalent (AAE)/g DW, the free ellagic acid content (EA) ranged from 49 to 94 µg/mL, and the ellagitannins (ETs) ranged from 242 to 340 µg/mL. For both cultivars, PUAE extracts had higher ET content and a lower EC50, while the decoctions had slightly higher TPC, RSA, and free EA amounts. Principal component analysis (PCA) highlighted the direct correlation between the ET content and the tyrosinase enzyme inhibition (lower values of EC50). These findings suggest the potential use of both these natural extracts as low-cost lightening and/or anti-browning ingredients exploitable in several formulations (e.g., cosmetics) or extemporarily usable.

In this research, for the first time, an alternative method to produce Ribes nigrum bud derivatives is presented. Pulsed ultrasound-assisted extraction (PUAE), using a food-grade solvent according to green chemistry principles, has been employed and compared to the conventional extraction method. Traditionally, bud derivatives, a category of botanicals marketed as plant food supplements in the European Community, are produced by macerating meristematic tissues of trees and plants mainly spontaneously collected. Buds are a challenging raw material for the UAE, since meristematic tissues are much softer and fragile than their corresponding adult phenological stage. It is therefore important to assess whether the polyphenolic fraction, very susceptible to degradation, is conserved after UAE. Untargeted polyphenolic fingerprints (UV-Visible and fluorescence) coupled with chemometrics are employed to quickly screen the best extraction conditions, evaluated by the design of experiment (DoE) method. The polyphenolic fraction of the optimized PUAE extract was quantified by targeted HPLC fingerprint and its antiradical activity was determined. PUAE on a lab pilot reactor was proven to be the most practical approach for a rapid (20 min vs. 21 days maceration) and efficient extraction of bioactive polyphenolics from Ribes nigrum buds, encouraging the scale up to an industrial plan.