Global interest in yacon (Smallanthus sonchifolius) is growing due to its potential as a functional food, attributable to its unique profile of bioactives and high fructooligosaccharide (FOS) content, which vary between cultivars. Our objective was to conduct a comprehensive chemical and nutritional analysis of New Zealand yacon concentrate (NZYC)—a sweet syrup derived from the roots of cultivar ‘New Zealand’, which was first grown in the 1980s. The major minerals in NZYC were potassium, phosphorus, and calcium. The FOS content ranged from 17.6 to 52.7 g/100g. Total phenolic content ranged from 565 to 785 mg gallic acid equivalents per 100 g; chlorogenic acid and caffeic acid were the major phenolic compounds. The major amino acids were L-arginine, L-glutamic acid, L-proline, L-aspartic acid, and asparagine. The major organic acids were citric, malic, quinic, and fumaric acids. Antioxidant activity ranged from 1084.14 to 3085.78 mg Trolox equivalents per 100 g depending on the assay used. The glycaemic index (GI) value was 40 ± 0.22, classifying it as a low-GI food. These results support the classification of NZYC as a nutraceutical food product for future diet therapy applications.

Yacon (Smallanthus sonchifolius), a sustainable foodstuff, is perceived as a functional food because it contains biologically active components, e.g., fructooligosaccharides (FOS), inulin, and phenolic compounds that may provide physiological benefits beyond basic nutrition to reduce the risk of chronic diseases. There is a growing public interest in why and how to use yacon. Yacon, originally from South America, has been grown in New Zealand (NZ) since the 1980’s. NZ-produced yacon concentrate NZFOS+ contains the purest natural prebiotic FOS. Our study aimed to examine the phytochemical contents of NZFOS+ and its health-related properties. The glycemic index of yacon concentrate was measured by ISO 26642:2010(E) (n = 10). Total phenolic and flavonoid contents were measured by the spectrometric method. The chlorogenic acid content and phenolic profiling were measured using the liquid chromatography coupled with mass spectrometry (LC-MS). The antioxidant activity of the yacon concentrate and Manuka honey were compared using the cupric reducing antioxidant capacity (CUPRAC), ferric ion reducing antioxidant power (FRAP), and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays. The results indicated that compared to Manuka honey, yacon concentrate has a lower glycemic index (40 vs. 52); a higher content of total phenolic (5430 mg vs. 744 mg GAE/100 g), total flavonoid (329 mg vs. 22 mg QE/100 g), and chlorogenic acid (11.88 μg vs. 0.08 μg CA/g); and across all assays observed, a significantly higher antioxidant capacity (CUPRAC assay, 892 mg vs. 52.6 mg TE/100 g; FRAP assay, 633 mg vs. 47 mg TE/100 g; DPPH assay, 383 mg vs. 22 mg TE/100 g, respectively). Yacon concentrate has proven potential health benefits and applications associated with the maintenance of health and wellbeing and prevention of chronic diseases. Further investigations are needed for human studies and new applications and use of yacon concentrate. Yacon concentrate (NZFOS+) has potential markets in the development of new food products and new diet therapy applications, e.g., in the form of syrup, and functional prebiotic drinks.

The increasing awareness of the overall health consumers, in particular young people, has driven a shift from fruit juices and carbonated drinks to functional beverages. Functional drinks utilising new ingredients (e.g., prebiotics and probiotics) have now created a niche in the food industry. Yacon (Smallanthus sonchifolius), a perennial plant of the family Asteraceae native to the Andean regions in South America, is an abundant source of prebiotic fructo-oligosaccharides (FOS). Yacon was introduced into New Zealand in the 1980s. Yacon fruits are harvested and made into juice concentrate with high-pressure low-temperature processes to reserve the bioactive components. Recently, yacon concentrate (NZFOS+) was awarded Nutra Ingredients Asia Awards. This research aimed to incorporate yacon concentrate to the formulation of functional drinks to improve the health-related properties. By using yacon concentrate as the main ingredients, three prototypes of functional drinks have been developed: yacon with collagen, yacon with blackcurrant, and yacon with vitamin(c). Sensory evaluation for yacon collagen and yacon blackcurrant drinks was conducted by a nine-point hedonic scale from one (very slight perception) to nine (very intense perception). The antioxidant activities of three yacon drinks were evaluated using the cupric ion reducing antioxidant capacity (CUPRAC) assay and ferric ion reducing antioxidant power (FRAP) assay. Yacon collagen and yacon blackcurrant drinks were sensorily acceptable, with ratings above the middle point of the scores (all ratings > 5, n = 50) for four sensory attributes (appearance, sweetness, flavour, and overall liking). The antioxidant capacity of yacon collagen, yacon blackcurrant, and yacon vitamin(c) drinks were 317 mg/368 mg/482 mg TE/100 g (CUPRAC assay) and 163 mg/258 mg/427 mg TE/100 g (FRAP assay), respectively. The antioxidant capacities of yacon blackcurrant and yacon vitamin(c) were much higher than that of yacon-collagen because of the blackcurrant and vitamin c additions that enhanced the antioxidant capacity. The development of yacon functional drinks, as new dietotherapy applications of yacon concentrate (NZFOS+), could provide healthier food products for our consumers to exercise healthier food choices.

Yacon (Smallanthus sonchifolius) is an ancient Andean crop, traditionally used for both food and medicinal purposes, which was first introduced to New Zealand in the 1980s. In recent years, there has been growing global interest in yacon due to its potential as a functional food, which could be related to its unique profile of bioactive compounds, including prebiotic compounds, such as fructooligosaccharides (FOS), and phenolic compounds, which may have a range of activities, including antioxidant ones. FOS are non-digestible prebiotic carbohydrates, providing low calorific value and a positive impact on gut microflora. Our objective was to conduct a comprehensive chemical analysis of New Zealand yacon concentrate (NZYC, a sweet syrup produced from juice extracted from New Zealand grown yacon roots). Analysis included proximate composition, mineral, sugar, phenolic, amino acid, and organic acid profiles as well as antioxidant activity. The major mineral identified in NZYC was potassium (658 ± 6 mg/100 g), with significant concentrations of phosphorus, calcium, magnesium, and iron also determined by microwave plasma atomic emission spectrometry. The FOS content of NZYC ranged from 17.6 ± 0.3 to 52.7 ± 0.8 g/100 g as determined by high-performance liquid chromatography (HPLC), coupled with an evaporating light scattering detector (ELSD). The total phenolic content of NZYC ranged from 565 ± 9 to 785 ± 43 mg gallic acid equivalents per 100 g by the Folin-Ciocalteu method. Chlorogenic acid and caffeic acid were quantified as the major phenolic compounds. The major amino acids quantified were L-arginine, L-glutamic acid, L-proline, L-aspartic acid, and asparagine. The major organic acids quantified were citric, malic, quinic, and fumaric acids. The antioxidant activity of NZYC was determined by the ferric-reducing antioxidant power (FRAP) assay, cupric ion-reducing antioxidant capacity (CUPRAC) assay, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, and it was several times higher than both Manuka honey and goji berries by the basis of weight. These results support the classification of New Zealand yacon concentrate as a nutraceutical food product and its use in further development of novel food products.