A Sustainable Approach for the Valorization of Underutilized Date Fruits.

Secondary varieties of date fruits are often discarded because they do not have commercial value. However, their phytochemicals are very similar to those of the primary ones and therefore, they can be valorized as a source of compounds of interest, mainly phenols and dietary fiber. Their chemical composition changes with ripening, so their characterization throughout this process is of great significance. Date fruit samples were harvested at Khalal, Rutab, and Tamer stages, and a mixture of fruits from ornamental date trees was also analyzed. Aqueous and ethanolic extracts were studied for their phenolic composition. In aqueous extracts, phenols decreased with ripening, while in the ethanolic ones having higher phenolic content. Chelidonic acid, a γ-pyrone, was the major compound found in all extracts, but in the ethanolic ones, flavonoids were also present in similar amounts. After purification by adsorption chromatography, all extracts were assayed for their antimicrobial activity. Those from the Tamer stage showed the highest activity, especially against Gram-positive bacteria. The fibrous residues after aqueous and ethanolic extractions were also characterized. Their chemical composition suggested that they can be considered as a good source of prebiotic arabinoxylans and antioxidant fiber, whose antiradical activity correlated with their phenolic content. Date fruits from secondary varieties are promising as a worthwhile starting point for obtaining new value-added products.

Applications of Saponin Extract from Asparagus Roots as Functional Ingredient.

When replanting an asparagus field, the roots of the previous crop are crushed and incorporated into the soil, creating problems of autotoxicity and fungal infections. Asparagus roots can be considered as a valuable byproduct, since they are very rich in saponins (3-6%), compounds currently considered as bio-emulsifiers. The objective is to evaluate the emulsifying and foaming capacity of a saponin extract from asparagus roots (ARS) and compare it with other commercial extracts. ARS was obtained using a process patented by our research group. The results have shown that ARS has activity similar to Quillaja extract. Its critical micellar concentration falls between that of Quillaja and Tribulus extracts (0.064, 0.043, and 0.094 g/100 mL, respectively). Both emulsifying and foaming activities are affected by pH, salt, and sucrose to a similar extent as the other extracts. Additionally, it has demonstrated an inhibitory effect on pancreatic lipase, which is even better than the other two studied extracts, as indicated by its IC50 value (0.7887, 1.6366, and 2.0107 mg/mL for asparagus, Quillaja, and Tribulus, respectively). These results suggest that ARS could serve as a natural emulsifying/foaming agent for healthier and safer food products and as a potential aid in treatments for obesity and hyperlipidemia.

Asparagus Roots: From an Agricultural By-Product to a Valuable Source of Fructans.

Asparagus roots are by-products from asparagus cultivation and they could be considered one of the best sources of fructans. These polymers are interesting food ingredients for their prebiotic and immuno-stimulating characteristics. The aim of this work is to characterize the fructan profile from the roots of several asparagus varieties grown at different locations and pickled at three vegetative statuses in order to valorize these by-products as fructan source. Fructans were extracted with hot water and fractionated into three pools according to their molecular weight (MW). Their average MW was studied by HPSEC and their degree of polymerization by HPAEC. The fructan content was up to 12.5% on fresh weight basis, depending on variety and sampling date. The relative abundance of the three pools also depended on the picking moment as after the spear harvest period their total content and MW increased. The average MW of the three fractions was similar among varieties with 4.8, 8.4 and 9 sugar units, although fructans up to 30 units were identified by HPAEC. These characteristics make them similar to the commercialized Orafti®-GR inulin, a common additive to food products. Therefore, the concept of asparagus roots as cultivation waste must be changed to a new feedstock for sustainable agriculture and industry.

Asparagus Fructans as Emerging Prebiotics.

Commercial fructans (inulin and oligofructose) are generally obtained from crops such as chicory, Jerusalem artichoke or agave. However, there are agricultural by-products, namely asparagus roots, which could be considered potential sources of fructans. In this work, the fructans extracted from asparagus roots and three commercial ones from chicory and agave were studied in order to compare their composition, physicochemical characteristics, and potential health effects. Asparagus fructans had similar chemical composition to the others, especially in moisture, simple sugars and total fructan contents. However, its contents of ash, protein and phenolic compounds were higher. FTIR analysis confirmed these differences in composition. Orafti®GR showed the highest degree of polymerization (DP) of up to 40, with asparagus fructans (up to 25) falling between Orafti®GR and the others (DP 10-11). Although asparagus fructan powder had a lower fructan content and lower DP than Orafti®GR, its viscosity was higher, probably due to the presence of proteins. The existence of phenolic compounds lent antioxidant activity to asparagus fructans. The prebiotic activity in vitro of the four samples was similar and, in preliminary assays, asparagus fructan extract presented health effects related to infertility and diabetes diseases. All these characteristics confer a great potential for asparagus fructans to be included in the prebiotics market.

New Liquid Source of Antioxidant Phenolic Compounds in the Olive Oil Industry: Alperujo Water.

The current management of alperujo as the main solid by-product from the two-phase olive oil extraction system has led to the appearance of a new liquid effluent that until now was treated together with the alperujo itself. The composition and antioxidant properties of its bioactive components at different depths of the pond were studied using colorimetric and HPLC with UV and MS detectors, DPPH, reducing power and rancimat. The concentration of suspended solids varied between 1.71 and 8.49 g/L, total fat was between 0.74 and 1.47 g/L, and total phenols were found between 3.74 and 4.11 g/L, which included hydroxytyrosol, 3,4-dihydroxyphenylglycol and tyrosol as the main phenols. Two types of extracts were obtained through two industrial systems with ethyl acetate and by chromotography, with an average content in total sugars of 2.1% and 3.16%, total phenols of 17.9% and 28.6% and hydroxytyrosol of 51.5 and 79.0 mg/g of extract, respectively. The activity presented by the chromatographic extract was higher in terms of free radical sequestering capacity, reducing power and the inhibition of lipid oxidation. Obtaining bioactive extracts would improve the formulation of food with natural components and at the same time would be the first step in a biorefinery to improve the management of the new effluent.

Bioactive compounds in Mexican genotypes of cocoa cotyledon and husk.

A characterization of the phenolic profile of 25 cocoa genotypes established in a Mexican gene bank was carried out. From five different extraction methods commonly used for phenols, extraction with acidified methanol-water was chosen as the best to quantify the concentrations of theobromine and individual phenols in cocoa beans. High concentrations of individual and total phenols were found for genotypes native to Mexico (like RIM105, M031, and M033) or from Peru and Ecuador (INI10), but not the commercial mix (CAF), and were directly associated with their antioxidant activities. Despite the loss of some theobromine and phenols during fermentation, epicatechin remained in the fermented cotyledon in high concentrations. This study could help promote the commercialization of Mexican genotypes of cocoa and reports the possibility of upcycling fermented cocoa husks, which are rich in bioactive compounds and fiber, as novel functional extracts for use in food formulation or for nutraceutical purposes.

Authentication of fattening diet of Iberian pig according to their triacylglycerols profile from subcutaneous fat.

Triacylglycerols of 50 samples of subcutaneous fat of Iberian pigs reared extensively on two different feeding systems: montanera (M) and cebo (C) have been analysed by gas chromatography flame ionization detector. The lipids were extracted by melting from subcutaneous fat into microwave oven. The fat was then filtered and dissolved in hexane. This analysis was performed on a column (30 m x 0.25 mm i.d.) coated with a bonded stationary phase DB-17HT (50% phenyl-50% methylpolysiloxane; 0.15 microm film thickness) with hydrogen (2.1 mL min(-1)) as a carrier gas, programmed temperature was kept at 320 degrees C, and was then raised to 350 degrees C at a rate of 2.0 degrees C min(-1) and flame ionization detector. By using the triacylglycerols as chemical descriptors, pattern recognition techniques were applied to differentiate between montanera and cebo fattening diet of Iberian pig. Triolein, palmitoyl-stearyl-oleoyl glycerol and di-oleoyl-linoleoyl glycerol were found to be the most differentiating variables.