Currently, there is an increasing interest to valorise agri-food waste containing bioactive compounds with potential health benefits. In this paper, the recovery of functional molecules from apple pomace, the most abundant by-product of the apple processing industry, was carried out by ultrasound-assisted extraction (UAE) on fresh and freeze-dried samples. UAE extract, obtained by double extraction of freeze-dried apple pomace, was subjected to chromatographic and spectrophotometric characterization. It showed good levels of total phenol content, high antioxidant activity, and interesting antioxidant compounds (quercetin derivatives, chlorogenic acid, phloridzin). Subsequently, freeze-dried apple pomace, containing 40.19% of dietary fibre, was used as a fortifying agent for beef burgers (4% and 8%). The results concerning colour and sensory analysis of the fortified products were graded even better than the control (0%). The improved fibre and phenol content, together with the neutral flavour, represent the most interesting characteristics of fortified burgers. The results confirm that UAE was a successful technique for extracting phenol compounds and that the addition of apple pomace represents a valid approach to increase the health properties and palatability of beef burgers, including for consumers who do not like meat.

A carotenoid-rich extract from Lycium barbarum L. was added to extra virgin olive oil (EVOO), obtaining a carotenoid-enriched oil (EVOOCar). The oxidative stability of EVOO and EVOOCar was evaluated during long-term storage of 28 weeks at room temperature, by measuring some classical parameters (acidity and peroxide values, spectrophotometric coefficients, fatty acid composition) and the content of minor compounds (i.e., α-tocopherol and lutein). At the end of the storage, higher content (p < 0.01) of α-tocopherol in EVOOCar in respect to EVOO were observed. Zeaxanthin dipalmitate, the most abundant carotenoid compound of Goji berries, decreased slightly (p < 0.05) in EVOOCar until the end of the storage. In regard to polyphenols, an ultra-high-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (UHPLC/QTOF-MS) using untargeted metabolomics was carried out. This latter approach discriminated the two oil samples during long-term storage, allowing to identify also the phenolic classes most exposed to significant variations during storage (i.e., mainly lignans and flavones). Besides, the addition of Goji carotenoids preserved the stability of tyrosol equivalents in EVOOCar during long-term storage. These results highlighted that the enrichment of EVOO with a carotenoid-rich extract can improve the shelf-life and nutritional value of added-oil, protecting EVOO natural antioxidants during long-term storage.

In recent years, there is an increasing interest in high-quality extra virgin olive oils (EVOOs) produced from local cultivars. They have particular chemical/organoleptic characteristics and are frequently subjected to fraud, whereby the control of quality requires a powerful varietal check. In the present research, triacylglycerols (TAGs) and volatiles have been studied as chemical markers for the authentication of EVOO samples from four Italian varieties of Olea europea (Dolce Agogia, Frantoio, Leccino, and Moraiolo). The monocultivar EVOO samples have been subjected to a chemical–enzymatic chromatographic method in order to perform a stereospecific analysis, an important procedure for the characterization of TAG of food products. The results, combined with chemometric analysis (linear discriminant analysis, LDA), were elaborated in order to classify Italian EVOO monocultivar samples. In accordance with the total and intrapositional fatty acid (FA) composition of TAG fraction, the results were allowed to carry out a varietal discrimination. In addition, volatile compounds were also determined by solid-phase micro-extraction gas chromatography–mass spectrometry analysis. All EVOO samples were correctly classified when TAG stereospecific data and volatile results were elaborated by the LDA procedure, even if volatile compounds showed a higher discriminant power.

Milk, milk-based products, and milk derivatives represent an important group of food commodities, with high nutritional value and widely consumed by large segment of consumers, including pregnant women, newborns, children, and the elderly. Food authentication is a rapidly growing field because of increasing consumer awareness regarding food quality and safety. This review attempts to critically summarize the status of direct and indirect analysis of the molecular species of triacylglycerols (TAG) used to assess the authenticity of milk. Identification and quantification of TAG molecular species in milk fat can be accurately performed even though analytical approaches focused on fraud evaluation should be developed. Recent analytical breakthroughs and novel techniques are discussed, along with their applications in milk authentication.

The characteristics of plum fruits of three different species were investigated throughout their development (including over-ripening). The content of primary and secondary metabolites was expressed as amount per gram DW (dry weight) and per fruit in order to obtain information about the balance between their synthesis and dissimilation at different stages of fruit development. In all the plums, during the first stages of development, glucose was the most abundant sugar, whereas sucrose increased during ripening. There was no decrease in malate content per fruit before the commercial harvesting time of any of the plums, whereas a decrease was observed during over-ripening. In general, both the total phenol content and the contents of individual phenols in the flesh expressed on gram DW decreased throughout development, whereas their content per fruit increased, indicating that these decreases were due to a dilution effect arising from the expansion of the flesh. During the development of the flesh, the increase in the contents of the investigated metabolites per fruit shows that there was no net dissimilation of malate up to commercial harvest and of phenols throughout fruit development. Good correlations between the content of phenols to antioxidant activity were found. Shiro flesh, during the last part of fruit development, had lower total carbohydrate and polyphenol contents, lower antioxidant activities, and a higher malate content than the flesh of the other two genotypes.

In recent years, agricultural and industrial residues have attracted a lot of interest in the recovery of phytochemicals used in the food, pharmaceutical, and cosmetic industries. In this paper, a study on the recovery of phenol compounds from Lycium spp. leaves is presented. Ultrasound-assisted extraction (UAE) and microwave-assisted extraction (MAE) have been used with alcoholic and hydroalcoholic solvents. Methanolic UAE was the most successful technique for extracting phenols from Lycium leaves, and we used on leaves from L. barbarum and L. chinense cultivated in Italy. The extracts were then characterized as regards to the antioxidant properties by in vitro assays and the phenol profiling by a high performance liquid chromatography-diode array detector (HPLC-DAD). Chlorogenic acid and rutin were the main phenol compounds, but considerable differences have been observed between the samples of the two Lycium species. For example, cryptochlorogenic acid was found only in L. barbarum samples, while quercetin-3-O-rutinoside-7-O-glucoside and quercetin-3-O-sophoroside-7-O-rhamnoside only in L. chinense leaves. Finally, multivariate statistical analysis techniques applied to the phenol content allowed us to differentiate samples from different Lycium spp. The results of this study confirm that the extraction is a crucial step in the analytical procedure and show that Lycium leaves represent an interesting source of antioxidant compounds, with potential use in the nutraceutical field.

Recently, much interest has been focused on Moringa oleifera L., a highly versatile and sustainable plant. In addition to its nutritional properties, numerous bioactive compounds have been identified in M. oleifera leaves, for which healthy properties have been reported. In the present research, the impact of ultrasound-assisted extraction (UAE) on the recovery of the bioactive compounds from leaves was investigated. Firstly, an experimental design approach has been used to highlight the influence of some extraction parameters (solvent, solvent/dry leaves ratio, temperature, time) on phenol compound recovery and antioxidant activity. Solvent composition was the most influential factor; in fact, the presence of water in the solvent (50:50, v/v) corresponded to an increase in the extraction performance. The liquid/solid ratio (L/S) also influenced the extraction process; in fact, the total phenol content reached 13.4 mg gallic acid equivalent (GAE)/g dry matter (DM) in the following UAE conditions: 50% water, 60:1 L/S ratio, 60 °C, 60 min. In order to quantify flavonols, hydroalcoholic extracts were analysed by HPLC-DAD (high performance liquid chromatography-diode array detector). In the flavonol class, the glycosidic forms of quercetin and kaempferol were mainly detected. Their content ranged from 216.4 µg/g DM of quercetin 3-O-rhamnoside to 293.9 µg/g DM of quercetin 3-O-(6″-O-malonyl)-β-D-glucoside. In summary, the leaves of M. oleifera are a potential natural source of bioactive compounds, proving to be very promising for the development of health-promoting food supplements.

Red Delicious apple pomace was produced at laboratory scale with a domestic blender and different non-conventional extraction techniques were performed to isolate phenolic compounds, such as ultrasound-assisted extraction (UAE), ultraturrax extraction (UTE), accelerated solvent extraction (ASE) and pulsed electric field (PEF) extraction pre-treatment. Total phenolic content (TPC) was determined by Folin–Ciocalteu assay. Phloridzin, the main phenolic compound in apples, was determined by chromatographic analysis Q-TOF-LC/MS. The results obtained with these techniques were compared in order to identify the most efficient method to recover polyphenols. The highest value of TPC (1062.92 ± 59.80 µg GAE/g fresh apple pomace) was obtained when UAE was performed with EtOH:H2O (50:50, v/v), while ASE with EtOH:H2O (30:70, v/v) at 40 °C and 50% of flush was the most efficient technique in the recovery of phloridzin. The concentration of the main phenolic compounds ranged from 385.84 to 650.56 µg/g fresh apple pomace. The obtained results confirm that apple pomace represents an interesti-ng by-product, due to the presence of phenolic compounds. In particular, phloridzin could be considered a biomarker to determine the quality of numerous apple products. Therefore, this research could be a good starting point to develop a value-added product such as a functional food or nutraceutical.