Molecularization of Foam-Active Saponins from Sugar Beet Side Streams (Beta vulgaris ssp. vulgaris var. altissima)

Antihyaluronidase and Antioxidant Potential of Atriplex sagittata Borkh. in Relation to Phenolic Compounds and Triterpene Saponins

The genus Atriplex provides species that are used as food and natural remedies. In this work, the levels of soluble phenolic acids (free and conjugated) and flavonoids in extracts from roots, stems, leaves and flowers of the unexplored Atriplex sagittata Borkh were investigated by LC-ESI-MS/MS, together with their antioxidant and antihyaluronidase activity. Phenolic acids were present in all parts of A. sagittata; and were most abundant in the leaves (225.24 μg/g dw.), whereas the highest content of flavonoids were found in the flowers (242.71 μg/g dw.). The most common phenolics were 4-hydroxybenzoic and salicylic acids, kaempferol-3-glucoside-7-rhamnoside, kaempferol-3-rutinoside and the rare narcissoside, which was present in almost all morphotic parts. The stem extract had the highest antioxidant activity and total phenolic content (611.86 mg/100 g dw.), whereas flower extract exerted the most potent antihyaluronidase effect (IC₅₀ = 84.67 µg/mL; control-quercetin: IC₅₀ = 514.28 μg/mL). Phytochemical analysis of the flower extract led to the isolation of two triterpene saponins that were shown to be strong hyaluronidase inhibitors (IC₅₀ = 33.77 and 168.15 µg/mL; control-escin: IC₅₀ = 307.38 µg/mL). This is the first report on the presence of phenolics and saponins in A. sagittata. The results suggest that both groups of metabolites may contribute to the overall activity of this plant species.

Physicochemical and sensory properties of malt beverage containing sugar beet saponins

Aqueous two-phase system (ATPS) composed of polyethylene glycol (PEG) and K2HPO4 solutions was used to extract saponin from sugar beet root. Extraction yield, purity and foam capacity of saponin were optimized according to response surface methodology (RSM). Analysis of liquid chromatography-mass spectrometry (LC-MS) showed that purified saponins were composed of hederagenin, akebonoic acid and oleanolic acid. Addition of 0.02 g sugar beet root saponin to one liter of malt beverage caused a considerable increase in foam volume and stability compared to malt beverage samples containing 0.1 g/L propylene glycol alginate (PGA). Malt beverages containing saponin showed higher turbidity, bitterness and overall sensory acceptance. Moreover, no significant changes in malt drink pH and °Brix were observed due to saponin addition. Adding lemon flavor caused a decrease in foam stability and sensory acceptance of malt beverage containing saponin compared to PGA containing ones. Less saponin content is suggested for flavored malt drinks.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-022-05517-x.

Sensory evaluation, chemical structures, and threshold concentrations of bitter-tasting compounds in common foodstuffs derived from plants and maillard reaction: A review

The bitterness of foodstuffs is often associated with toxicity, which negatively influences product acceptability. However, bitter compounds have many benefits, and a slight bitter taste is sometimes favored. In this review, we summarize the methods used to isolate and evaluate the taste of bitter compounds in different foods. The chemical structures and threshold concentrations of these compounds are also recapped. Although the structures and thresholds of many bitter compounds have been confirmed, further studies are needed to develop detailed bitter-masking strategies and establish the relation between functional groups (hetero-cyclic substituents and bonding types) and taste quality. Furthermore, a comprehensive bitterness database and chemometric data must be provided in order to quickly assess the bitterness of unfamiliar products.

Fast and Sensitive LC-MS/MS Method for the Quantitation of Saponins in Various Sugar Beet Materials

An LC-MS/MS method was developed for the simultaneous quantitative analysis of the following 11 triterpene saponins within different sugar beet materials and plant compartments: betavulgaroside I (1), betavulgaroside II (2), betavulgaroside III (3), betavulgaroside IV (4), betavulgaroside VIII (5), boussingoside A2 (6), 3-O-[β-d-glucopyranosyl-(1 → 2)-(β-d-xylopyranosyl-(1 → 3))-β-d-glucuronopyranosyl]-28-O-β-d-glucopyranosyl-3β-hydroxyolean-12-en-28-oic acid (7), betavulgaroside V (8), chikusetsusaponin IVa (9), calenduloside E (10), and ginsenoside R0 (11). Our results showed highly varying amounts of saponins within different varieties, roots, and leaves as well as different plant compartments. The amounts for sugar beet roots were in the range of 862 mg/kg to 2 452 mg/kg. They were mostly higher for leaves compared to roots of the same variety with amounts ranging from 907 mg/kg to 5 398 mg/kg. Furthermore, the occurrence of sugar beet saponins within different side streams was examined; in this context, sugar beet fiber contained the highest amounts of saponins for all investigated plant constituents and byproduct streams with a total amount of 12.7 g/kg. Finally, this is the first publication about the occurrence of individual saponins in sugar beets.