Effects of fructans-containing yacon (Smallanthus sonchifoliusPoepp & Endl.) flour on caecum mucosal morphometry, calcium and magnesium balance, and bone calcium retention in growing rats

Extraction, physicochemical properties, bioactivities and application of natural sweeteners: A review

Natural sweeteners generally refer to a sweet chemical component directly extracted from nature or obtained through appropriate modifications, mainly secondary metabolites of plants. Compared to the first-generation sweeteners represented by sucrose and the second-generation sweeteners represented by sodium cyclamate, natural sweeteners usually have high sweetness, low-calorie content, good solubility, high stability, and rarely toxic side effects. Historically, researchers mainly focus on the function of natural sweeteners as substitutes for sugars in the food industry. This paper reviews the bioactivities of several typical natural sweeteners, including anti-cancer, anti-inflammatory, antioxidant, anti-bacterial, and anti-hyperglycemic activities. In addition, we have summarized the extraction, physicochemical properties, and application of natural sweeteners. The article aimed to comprehensively collate vital information about natural sweeteners and review the potentiality of tapping bioactive compounds from natural products. Hopefully, this review provides insights into the further development of natural sweeteners as therapeutic agents and functional foods.

Investigating the potential of yacon (Smallanthus sonchifolius) juice in the development of organic apple-based snacks

This study investigates the potential of yacon (Smallanthus sonchifolius) juice for the development of prebiotic-rich organic apple-based snacks. Yacon syrup, primarily composed of fructan, inulin, fructooligosaccharides (FOS), and free sugars, represents a promising nutraceutical product. Its great potential in food processing, particularly as an innovative source of prebiotics, has been demonstrated both in vitro and in vivo since it is fermented specifically by lactobacilli and bifidobacteria. Our objective was to explore the feasibility of employing vacuum impregnation process to incorporate yacon juice into organic apples, followed by hot air drying for the formulation of dried organic apple-based snacks with health-enhancing attributes. We assessed the prebiotic and physicochemical characteristics of the impregnated snacks, also considering 50 days of storage at room temperature. Vacuum impregnation and air drying produced dried apple slices impregnated with yacon juice with good quality and stability. Higher levels of fructan (16-fold difference compared to non-impregnated apples) in the apple slices increased their prebiotic potential, promoting the growth and viability of cells within simulated intestinal fluid, including strains of Bifidobacterium animalis subsp. lactis BB -12, Bifidobacterium breve DSM 20091, Bifidobacterium longum subsp. infantis DSM 20088, Lacticaseibacillus rhamnosus GG and Lacticaseibacillus rhamnosus C112, even after prolonged storage. Remarkably, the physicochemical parameters of the impregnated and dried apple slices remained nearly constant and akin to the control samples. Therefore, the combination of vacuum impregnation and air drying has the potential to be used to produce enriched prebiotic organic apple snacks, providing consumers with additional health benefits, including enhanced gut health, with its associated implications, and increased satiety. This innovation could contribute to the development of health-promoting food products with improved nutritional profiles.

Yacon (Smallanthus sonchifolius) and kefir improved intestinal and bone health but without symbiotic benefits in rats

Kefir is a natural source of probiotics, and yacon (Smallanthus sonchifolius) is a tuberous root rich in fructooligosaccharides, with prebiotic properties. We hypothesized that kefir and yacon can improve bone and intestinal health and that their synbiotic effects will enhance these benefits. The properties of yacon and kefir and their association were evaluated in the intestinal and bone health in rats. Forty Wistar male rats were divided into 4 groups (n = 10): control (C), kefir (K), yacon (Y), and yacon + kefir (YK) and received an AIN-93 M diet containing 50% of the daily recommendation of calcium for 42 days. Group K received 1 mL/day of kefir containing 10⁸ CFU/mL; group Y received yacon flour (5% fructooligosaccharides); and the YK group received the same treatment as the Y and K groups. Urine and feces were collected to determine the calcium balance. Serum biomarkers of bone formation and resorption, osteocalcin, N telopeptides of collagen type I and C-telopeptide of collagen type I, intraluminal pH, intestinal permeability, and secretory immunoglobulin A were evaluated. Yacon reduced intraluminal pH alone or in association with kefir (groups Y and YK). Yacon also improved intestinal permeability (lowered lactulose and mannitol excretion) and increased calcium balance and osteocalcin, a biomarker of bone formation. In turn, K improved immunity by increasing secretory immunoglobulin A secretion and reducing bone resorption biomarkers (C-telopeptide of collagen type I and N telopeptides of collagen type I). Thus, yacon and kefir had beneficial effects on intestinal and bone health; however, the association between them did not demonstrate a synbiotic effect.

When Incorporated into Fruit Sorbet Matrix, Are the Fructans in Natural Raw Materials More Beneficial for Bone Health than Commercial Formulation Added Alone?

We assessed the extent to which fructans from various sources and added in various forms (raw materials in diet alone or incorporated into a strawberry matrix) differ in their effectiveness towards selected parameters related to bone health under calcium hypoalimentation in growing female Wistar rats. The aim of this study was to evaluate the levels of selected parameters involved in calcium metabolism, in response to a 12-week restriction of Ca intake: serum ions (Ca, Mg, P); the activity of alkaline phosphatase—using a BS 120 analyzer; the markers of bone turnover (osteocalcin, CTX; using a Rat-MidTMOsteocalcinEIA Kit and RatLapsTMEIA, respectively); and the bone mineral content (BMC) and density (BMD), using a Norland Excell Plus Densitometer. Among the examined markers, the CTX concentration increased dramatically under calcium hypoalimentation. The presence of Jerusalem artichoke (independently of the form of addition) and yacon root powder (with strawberry sorbet matrix) in the rats’ diet led to a significantly lower CTX concentration than was observed in the low-calcium control group. The type of fructan influenced the bone mass content. When fructan was added to the low-calcium diet as an ingredient of sorbet, it exerted more pronounced effects on the biochemical parameters of bone metabolism than when added alone, in the growing-female-rat model.

Medicinal Plants, Phytochemicals, and Their Impacts on the Maturation of the Gastrointestinal Tract

The gastrointestinal tract (GIT) is the first point of contact for ingested substances and thus represents a direct interface with the external environment. Apart from food processing, this interface plays a significant role in immunity and contributes to the wellbeing of individuals through the brain-gut-microbiota axis. The transition of life from the in utero environment, to suckling and subsequent weaning has to be matched by phased development and maturation of the GIT; from an amniotic fluid occupancy during gestation, to the milk in the suckling state and ultimately solid food ingestion at weaning. This phased maturation of the GIT can be affected by intrinsic and extrinsic factors, including diet. Despite the increasing dietary inclusion of medicinal plants and phytochemicals for health benefits, a dearth of studies addresses their impact on gut maturation. In this review we focus on some recent findings mainly on the positive impact of medicinal plants and phytochemicals in inducing precocious maturation of the GIT, not only in humans but in pertinent animals. We also discuss Paneth cells as mediators and potential markers of GIT maturation.

Yacon as an alternative host plant for Encarsia formosa mass-rearing: validating a multinomial theorem for bootstrap technique in life table research

BACKGROUND

Yacon (Smallanthus sonchifolius) is a broadleaf host plant suitable for rearing the greenhouse whitefly, Trialeurodes vaporariorum (Westwood). Here, the possibility of using yacon as an alternative host plant for production of the parasitoid, Encarsia formosa Gahan, one of the most important natural enemies of whiteflies, was explored. Data on the demographic characteristics, parasitism rate, and host-feeding rate were collected and analyzed using the TWOSEX-MSChart, CONSUME-MSChart, and TIMING-MSChart computer programs, and then contrasted with comparable data from the more commonly utilized host plant, tobacco.

RESULTS

Higher fecundity (F) (190.13 eggs/female) and more oviposition days (O_d ) (16.60 days) were observed in E. formosa when yacon was used as the host plant for rearing T. vaporariorum, compared with when tobacco was used (F = 150.13 eggs/female, O_d = 15.27 days). The intrinsic rate of increase (r), finite rate of increase (λ), and net reproduction rate (R₀ ) were significantly higher in E. formosa parasitizing T. vaporariorum reared on yacon compared with those parasitizing tobacco-reared T. vaporariorum. Furthermore, the net host-feeding rate (C₀ = 40.87 prey/parasitoid), net killing rate (Z₀ = 239.73 prey/parasitoid), and finite killing rate ( υ  = 0.2560/day) for E. formosa on yacon-reared whiteflies were significantly higher than those from tobacco-reared whiteflies.

CONCLUSION

Our results showed that yacon is more suitable than tobacco as a host plant for mass-rearing E. formosa for biological control programs to manage whiteflies. An innovative application of the multinomial theorem for calculating the exact probability of bootstrap samples in life table research was also introduced. © 2021 Society of Chemical Industry.

Calcium Bioavailability in the Soluble and Insoluble Fibers Extracted from Opuntia ficus indica at Different Maturity Stages in Growing Rats

Childhood and adolescence are crucial stages of life for bone health. Therefore, an adequate calcium intake and a healthy life style constitute the main strategies to prevent the risk of osteoporosis-related fractures during adulthood. It has been demonstrated that inclusion of indigestible carbohydrates in foods can help improve calcium absorption in growing stages. The objective of this study was to evaluate the effect of supplementation of soluble and insoluble fibers extracted from O. ficus indica cladodes on calcium bioavailability. Male Wistar rats 4-week old were fed diets added with soluble and insoluble fibers extracted from O. ficus indica cladodes at early and late maturity stages, as the only source of calcium. The mineral content, bone mineral density (BMD), physical, microstructural, and biomechanical properties of rat femurs were determined. The bones of rats fed with diets containing a soluble fiber extracted from O. ficus indica at early and late maturity stages exhibited better bone properties (resistance to fracture, microarchitecture, and calcium content) than control rats and rats fed with an insoluble fiber from O. ficusindica cladodes at both maturity stages. As expected, based on these results, the BMD values were higher in adolescent and pubertal rats fed with a diet containing the O. ficus indica soluble fiber. These results demonstrate that the soluble fiber from O. ficus indica cladodes is indeed a valuable source of bioavailable calcium, which contributes to improve physical, densitometric, biomechanical, and microstructural properties of bone in growing rats.

Faster Short-Chain Fatty Acid Absorption from the Cecum Following Polydextrose Ingestion Increases the Salivary Immunoglobulin A Flow Rate in Rats

Salivary immunoglobulin A (IgA) plays a vital role in preventing upper respiratory tract infections (URTI). In our previous study, we showed that the intake of carbohydrates increases the intestinal levels of short-chain fatty acids (SCFAs), which in turn increase salivary IgA levels. However, the mechanism underlying this phenomenon has not been fully elucidated. In this study, we investigated in rats the effect of polydextrose (PDX) ingestion on salivary IgA level and SCFA concentration in cecal digesta and the portal vein. Five-week-old rats were fed with a fiber-free diet (control) or with 40 g/kg of PDX for 28 days. Compared to the control, ingestion of PDX led to a higher salivary IgA flow rate (p = 0.0013) and a higher concentration of SCFAs in the portal vein (p = 0.004). These two data were positively correlated (r_s = 0.88, p = 0.0002, n = 12). In contrast, the concentration of SCFAs in cecal digesta and cecal digesta viscosity were significantly lower following PDX ingestion, compared to the control (p = 0.008 and 0.05, respectively). These findings suggest that the ingestion of PDX increases the absorption rate of SCFAs in the intestine through PDX-induced fermentation, which is accompanied by an increase in SCFA levels in the blood, and ultimately leads to increased salivary IgA levels.

A Sustainable Wholesome Foodstuff; Health Effects and Potential Dietotherapy Applications of Yacon

A sustainable food supply is an ever-growing public and planetary health concern influenced by food culture, food practices, and dietary patterns. Globally, the consumption of plant foods that offer physiological and biochemical benefits is increasing. In recent years, products made from yacon (Smallanthus sonchifolius) tubers and leaves, e.g., in the form of syrup, powder, and herbal tea, have steadily emerged with scientific evidence to validate their possible health claims. Yacon was introduced to New Zealand in 1966, and its products can now be produced on a commercial scale. This paper reviews literature published mainly in the last 10 years concerning the health-related properties of yacon as a wholesome foodstuff and its bioactive components, e.g., fructooligosaccharides. Literature was sourced from Web of Science, PubMed, EBSCO Health, and Google Scholar up to June 2019. The potential markets for yacon in the field of food technology and new dietotherapy applications are discussed. Furthermore, the unique features of New Zealand-produced yacon syrup are introduced as a case study. The paper explores the scientific foundation in response to the growing public interest in why and how to use yacon.

Fructan-Enriched Diet Increases Bone Quality in Female Growing Rats at Calcium Deficiency

This study was designed to determine the effect of feeding female rats with low-calcium diet containing one of three fructan sources (Jerusalem artichoke, yacon, Beneo Orafti Synergy1), on selected bone parameters. Growing Wistar rats were fed modified AIN-93 G diet enriched in fructan sources (8%), added alone or as a strawberry sorbet ingredient. Two of eight groups were a validation model, where the positive control group was fed with recommended calcium dose in the diet (RCD), and negative one - with low calcium diet (LCD). After 12 weeks, femoral Ca content, bone densitometry, architecture and hardness were examined. The positive effects on femoral Ca content and cortical thickness, area and content in distal part of bone was observed after feeding animals diet enriched in Jerusalem artichoke sorbet. Beneficial action on other bone tomographic parameters (particularly trabecular volumetric bone mineral density) in this part of femur were associated mainly with the consumption of the diet with sorbet containing yacon. Our results showed an important role of diet containing frozen strawberry desserts enriched in fructan sources in the maintenance of healthy bones of growing organism. It may suggest possible synergisms between fructans and bioactive substances of strawberry.

Phytochemical Properties and Nutrigenomic Implications of Yacon as a Potential Source of Prebiotic: Current Evidence and Future Directions

The human gut is densely populated with diverse microbial communities that are essential to health. Prebiotics and fiber have been shown to possess the ability to modulate the gut microbiota. One of the plants being considered as a potential source of prebiotic is yacon. Yacon is an underutilized plant consumed as a traditional root-based fruit in South America. Yacon mainly contains fructooligosaccharides (FOS) and inulin. Therefore, it has bifidogenic benefits for gut health, because FOS are not easily broken down by digestive enzymes. Bioactive chemical compounds and extracts isolated from yacon have been studied for their various nutrigenomic properties, including as a prebiotic for intestinal health and their antimicrobial and antioxidant effects. This article reviewed scientific studies regarding the bioactive chemical compounds and nutrigenomic properties of extracts and isolated compounds from yacon. These findings may help in further research to investigate yacon-based nutritional products. Yacon can be considered a potential prebiotic source and a novel functional food. However, more detailed epidemiological, animal, and human clinical studies, particularly mechanism-based and phytopharmacological studies, are lacking for the development of evidence-based functional food products.

Bioactive Potential of Andean Fruits, Seeds, and Tubers

The Andes is considered the longest continental mountain range in the world. It covers 7000km long and about 200-700km wide and an average height of about 4000m. Very unique plant species are endemic of this area including fruits (e.g., lucuma, cherimoya, sweet pepino, sauco), roots and tubers (potatoes, sweet potatoes, yacón, chicuru, mashua, olluco, etc.), and seeds (quinoa, amaranth, tarwi, etc.). These crops have been used for centuries by the native population and relatively recently have gained the world attention due to the wide range of nutrients and/or phytochemicals they possess. In this chapter, main Andean fruits, seeds, and roots and tubers have been selected and detailed nutritional and functional information is provided. In addition, traditional and current uses are provided and their bioactive potential is reported based on published scientific literature.

Produto a base de yacon e modulação da microbiota, perfil de ácidos graxo e lipídico em ratas ovariectomizadas

RESUMO Objetivo: Este trabalho avaliou a modulação da microbiota gastrointestinal, do perfil de ácidos orgânicos e de lipídeos em ratas Wistar ovariectomizadas, sendo que algumas receberam dieta suplementada com 6% de fruto-oligossacarídeos e inulina, a partir do produto a base de yacon, e outras não. Métodos: Analisou-se o peso do ceco, pH e ácidos orgânicos, microbiota do conteúdo cecal, colesterol total e frações. Resultados: No grupo que recebeu a dieta suplementada durante todo o experimento ocorreu modulação benéfica da microbiota intestinal em função da fermentação dos fruto-oligossacarídeos/inulina, bem como aumento do perfil de lactato (p<0,05) e do nível de lipoproteina alta densidade (p<0,05). Conclusão: Isso sugere que o hábito de consumo contínuo do yacon tem potencial para modular a microbiota intestinal, o perfil de ácidos orgânicos e para diminuir as dislipidemias.

Yacon (Smallanthus sonchifolius) and Lactobacillus acidophilus CRL 1014 reduce the early phases of colon carcinogenesis in male Wistar rats

The modifying effects of aqueous yacon extract (AYE) and Lactobacillus acidophilus CRL 1014 against colon carcinogenesis induced by 1,2-dimethylhydrazine (DMH) in male Wistar rats were investigated. Animals were allocated into five groups: G1: untreated group; G2: DMH-treated group; G3: DMH+L. acidophilus-treated group; G4: DMH+AYE-treated group; G5: DMH+L. acidophilus and AYE-treated group. A significant reduction (p<0.05) in leukocyte DNA damage and in colonic cell proliferation was observed after the first DMH administration in G3 (probiotic), G4 (prebiotic) and G5 (synbiotic) groups. In this moment, a significant increase (p<0.05) in colonic apoptosis was also observed in G3 (probiotic) and G5 (synbiotic) groups. In special, at five months after DMH administrations, a significant reduction (p<0.05) in ACF development was observed in G3 (probiotic), G4 (prebiotic) and G5 (synbiotic) groups. Incidence of colon tumors was lower at five months in G4 (prebiotic) and G5 (synbiotic) groups but not in eight months after DMH administrations. In conclusion, the findings suggest that the oral treatments have potential effects as a chemopreventive agent against colon carcinogenesis on an early stage of tumor development.

Health properties of oca (Oxalis tuberosa) and yacon (Smallanthus sonchifolius)

Andean roots and tubers are underexploited crops; many contain compounds beneficial to health, so a greater knowledge of their properties is important for encouraging their consumption.

Fructo-oligosaccharides and iron bioavailability in anaemic rats: the effects on iron species distribution, ferroportin-1 expression, crypt bifurcation and crypt cell proliferation in the caecum

The present study investigated the effects of fructo-oligosaccharides (FOS) on the bioavailability of Fe from ferric pyrophosphate (FP), a water-insoluble compound, in Fe-deficient anaemic rats that were subjected to a Hb repletion assay. Male Wistar rats (n 64) were fed adequate or low (8 mg/kg) Fe diets for 15 d followed by 1 or 2 weeks of Fe repletion with diets providing 35 mg Fe/kg as ferrous sulphate (FS), FP or FP that was mixed with 7·5% FOS in the form of yacon flour or Raftilose P95 (RAF), a purified source of FOS. The effects of FOS were observed within the 1st week of the repletion period. Fe bioavailability was improved by FOS supplementation, as measured by Hb regeneration efficiency and hepatic Fe stores, which were more pronounced in the RAF group. Moreover, RAF supplementation resulted in a higher biological value relative to that of the FP group. FOS supplementation resulted in caecal enlargement, in addition to acidification and Fe species redistribution in the caecal contents relative to the control rats. These effects occurred concomitantly with decreased ferroportin (FPN)-1 expression in the caecal mucosa, which was similar in magnitude to that observed in the FS group. Caecum mucosal morphometry was influenced by FOS supplementation, whereas crypt fission and cell proliferation were highest in the caecum of the RAF group. These results reinforce the effects of FOS as Fe bioavailability enhancers in anaemic rats that are sustained by early changes in their caecal environment (decreased mucosal FPN-1 expression and increased Fe absorbability, crypt fission and cellularity).

Effects of Ficus thonningii extracts on the gastrointestinal tract and clinical biochemistry of suckling rats

BACKGROUND

Ficus thonningii is commonly used in traditional medicine across the African continent. We investigated the effects of crude Ficus thonningii extracts on growth, morphology and morphometry of the abdominal viscera and clinical biochemistry of neonatal rats.

MATERIALS AND METHODS

Forty, 6-day old Sprague Dawley rat pups were orally gavaged once daily with either low (50 mg.kg(-1) b.w) or high (500 mg.kg(-1) b.w) doses of aqueous or methanolic F. thonningii leaf extracts while the control received distilled water. After 7 days of treatment, the pups were euthanased and gross morphometric measurements of the abdominal visceral organs were recorded. Samples of the liver, caecum and proximal small intestine were processed for histology. Plasma biochemical parameters were analysed colorimetrically.

RESULTS

High methanolic doses of F. thonningii extracts exhibited trophic effects on the stomach while both aqueous and methanolic extracts had trophic effects on the ceacal mucosa of rats. No significant growth-promoting effects were observed in other visceral organs. Histological analysis revealed no mucosal damage or necrosis. Clinical biochemistry parameters were not abnormally altered. There was a significant decrease (p<0.05, ANOVA) in the plasma concentration of non-fasting glucose in the high methanolic group but triglycerides and cholesterol were unaltered.

CONCLUSION

The findings suggest that at low doses, F. thonningii extracts can be safely used without the risk of any disruption in the structural integrity of the neonatal rat GIT and function of the liver and kidneys.

Yacon effects in immune response and nutritional status of iron and zinc in preschool children

OBJECTIVE

The aim of this study was to evaluate the effect of yacon flour on iron and zinc nutritional status and immune response biomarkers in preschool children.

METHODS

Preschool children ages 2 to 5 y were selected from two nurseries and were placed into a control group (n = 58) or a yacon group (n = 59). The yacon group received yacon flour in preparations for 18 wk at a quantity to provide 0.14 g of fructooligosaccharides/kg of body weight daily. Anthropometric parameters were measured before and after the intervention and dietary intake was measured during the intervention. To assess iron and zinc status, erythrograms, serum iron, ferritin, and plasma, and erythrocyte zinc were evaluated. Systemic immune response was assessed by the biomarkers interleukin IL-4, IL-10, IL-6, and tumor necrosis factor-alfa (TNF-α). Intestinal immune response was analyzed by secretory IgA (sIgA) levels before and after the intervention. Statistical significance was evaluated using the paired t test (α = 5%).

RESULTS

Before and after the study, the children presented a high prevalence of overweight and an inadequate dietary intake of zinc and fiber. The yacon group presented with lower hemoglobin, mean corpuscular hemoglobin, and mean corpuscular hemoglobin concentration at the end of the study (P < 0.05). Erythrocyte zinc was reduced in both groups at the end of the study (P < 0.05). Yacon intake increased the serum levels of IL-4 and fecal sIgA (P < 0.05). The control group had lower serum TNF-α after the study period (P < 0.05).

CONCLUSION

Yacon improved intestinal immune response but demonstrated no effect on the nutritional status of iron and zinc in preschool children.

Yacon (Smallanthus sonchifolius): a functional food

Yacon (Smallanthus sonchifolius) is an Andean tuberous root that is regarded as a functional food given that it contains fructooligosaccharides (FOS), inulin and phenolic compounds. The consumption of FOS and inulin improves the growth of bifidobacteria in the colon, enhances mineral absorption and gastrointestinal metabolism and plays a role in the regulation of serum cholesterol. Furthermore, the literature reports that the consumption of these prebiotics promotes a positive modulation of the immune system, improving resistance to infections and allergic reactions. Certain studies have demonstrated the potential of yacon as an alternative food source for those patients with conditions that require dietary changes. This review intends to describe the potential of yacon as a prebiotic and its cultivation and industrial processing for human consumption.

Prebiotic inulin: Useful dietary adjuncts to manipulate the livestock gut microflora

In recent years, there has been a growing appreciation on the relevance of gastrointestinal microflora in both ruminants and non-ruminants owing to revelation of their role in several physiological functions including digestion, nutrient utilization, pathogen exclusion, gastrointestinal development, immunity system, gut gene expression and quality of animal products. The ban imposed on the use of antibiotics and hormones in feed has compelled animal researchers in finding an alternative which could overcome the issues of conventional feed additives. Though the concept of prebiotic was evolved keeping in mind the gastrointestinal flora of human beings, presently animal researchers are exploring the efficiency of prebiotic (inulin) for modulating the gut ecosystem of both ruminants and non-ruminants. It was revealed that prebiotic inulin is found to exhibit desirable changes in the gut of non-ruminants like poultry, swine, rabbit etc for augmenting gut health and improvement of product quality. Similarly, in ruminants the prebiotic reduces rumen ammonia nitrogen, methane production, increase microbial protein synthesis and live weight gains in calves. Unlike other feed additives, prebiotic exhibits its effect in multipronged ways for overall increase in the performances of the animals. In coming days, it is expected that prebiotics could be the part of diets in both ruminants and non-ruminants for enabling modulation of gut microflora vis a vis animals productivity in ecological ways.

Studies of chemical and enzymatic characteristics of Yacon (Smallanthus sonchifolius) and its flours

Due to the importance of studies on yacon related to health, its in natura pulp, in natura peel, pulp flour, and peel flour were chemically analyzed in terms of its centesimal composition, specific minerals, total dietary fiber and fractions, pH, total soluble solids, total titratable acidity, tannins, oxalic acid, and nitrate. The polyphenoloxidase and peroxidase enzymatic activities were evaluated for in natura pulp and peel only. Yacon pulp and peel flour presented average yield of 7.94% and 10.86%, respectively. The in natura pulp presented a higher moisture and carboydrate content and lower lipid, protein, total dietary fiber, and ash than those of the peel flour. The same pattern was observed for pulp flour when compared to peel flour. The highest tannin, nitrate, and oxalic acid levels were found in the peel flour, 15,304.5 mg.kg-1, 1,578.3 mg.kg-1, and 7,925.0 mg.kg-1 (wet weight), respectively. The polyphenoloxidase and peroxidase enzymes presented higher enzymatic activity in the yacon peel. Based on the results obtained, it can be said that the yacon and its derivatives are important dietary carbohydrate and mineral sources and contain antinutritional substance contents lower than those harmful to health.

Comparison of Yacon (Smallanthus sonchifolius) Tuber with Commercialized Fructo-oligosaccharides (FOS) in Terms of Physiology, Fermentation Products and Intestinal Microbial Communities in Rats

The yacon (Smallanthus sonchifolius) tuber was examined with regard to its prebiotic effects compared with commercialized fructo-oligosaccharides (FOS). A feed containing 10% yacon tuber, which is equivalent to 5% commercialized FOS in terms of the amount of fructo-oligosaccharides (GF2, GF3 and GF4), was administrated to rats for 28 days. The yacon diet changed the intestinal microbial communities beginning in the first week, resulting in a twofold greater concentration of cecal short-chain fatty acids (SCFAs). The SCFA composition differed, but the cecal pH in rats fed yacon tuber was equal to that in rats fed FOS. Serum triglycerides were lower in rats fed yacon compared with rats fed FOS and the control diet. Cecal size was greater with the yacon tuber diet compared with the control diet. The abundant fermentation in the intestines created a selective environment for the intestinal microbiota, which included Lactobacillus acidophilus, Bifidobacterium pseudolongum, Bifidobacterium animalis and Barnesiella spp. according to identification with culture-independent analysis, 16S rRNA gene PCR-DGGE combined with cloning and sequencing. Barnesiella spp. and B. pseudolongum were only found in the rats fed the yacon diet, while L. acidophilus and B. animalis were found in abundance in rats fed both the yacon and FOS diets. The genus Barnesiella has not previously been reported to be associated with yacon or FOS fermentation. We concluded that the physiological and microbiological effects of the yacon tuber were different from those of FOS. Differences in cecal size, blood triglycerides and microbial community profiles including their metabolites (SCFAs) between the yacon tuber and FOS were shown to be more greatly affected by the yacon tuber rather than FOS.

Prebiotic effects of yacon (Smallanthus sonchifolius Poepp. & Endl), a source of fructooligosaccharides and phenolic compounds with antioxidant activity

Thirty-five different yacon (Smallanthus sonchifolius Poepp. & Endl) accessions were evaluated as potential alternative sources of fructooligosaccharides (FOS) and phenolic type natural antioxidants. FOS, total phenolics (TPC) and antioxidant capacity (AC) contents in the ranges of 6.4-65g/100g of dry mater (DM), 7.9-30.8mg chlorogenic acid (CAE)/g of DM and 23-136μmol trolox equivalente (TE)/g DM were found. Accession AJC 5189 sparked attention for its high FOS content while DPA 07011 for its high TPC and AC. In addition, the prebiotic effect of yacon FOS was tested in vivo with a guinea pig model. A diet rich in yacon FOS promoted the growth of bifidobacteria and lactobacilli, resulting in high levels of short chain fatty acids (SCFAs) in the cecal material and enhancement of cell density and crypt formation in caecum tissue, being indicative of colon health benefits. This study allowed identification of yacon cultivars rich in FOS, AC and/or FOS and AC for nutraceutical applications.

Yacon (Smallanthus sonchifolius)-derived fructooligosaccharides improves the immune parameters in the mouse

Owing to its high contents of fructooligosaccharides (FOSs), the yacon (Smallanthus sonchifolius) root is used in traditional Andean medicine as a substitute for cane sugar in diabetes and for obesity prevention. This study was designed to test the hypothesis that regular consumption of yacon works to improve the immune system. BALB/c mice were fed with the AIN-93 diet supplemented with 5% commercial FOS or either 3% or 5% yacon FOS for 30 consecutive days. Animals in the control group were fed with nonsupplemented ration. Food intake; weight gain; serum levels of IgA, IgM, and IgG; levels of fecal IgA, production of nitric oxide by peritoneal macrophages, frequencies of T and B lymphocytes in the spleen and peripheral blood, T-cell proliferation, and cytokine production were evaluated in all groups. No significant differences were observed in food intake and weight gain when the experimental and control groups were compared. Also, serum levels of IgA, IgM, and IgG; nitric oxide production in peritoneal macrophages; frequencies of T and B lymphocytes in the spleen and peripheral blood; T-cell proliferation; and production of interleukin (IL)-4, interferon-γ, IL-10, and tumor necrosis factor α did not differ in the different groups. The intake of FOS, however, led to a significant reduction of the proinflammatory cytokine IL-1β in macrophage cultures and elevation of the levels of fecal IgA. Together, these results indicate that the daily consumption of yacon does not exert negative effects on the immune system, helps to preserve an anti-inflammatory state in phagocytic cells, and improves mucosal immunity, possibly preventing the risks associated with autoimmune and metabolic diseases.

The in vitro digestibility and absorption of magnesium in some edible seaweeds

BACKGROUND

Many edible seaweeds are rich in magnesium (Mg). However, Mg absorption is low in some seaweeds because fibers in these seaweeds suppress Mg absorption. We hypothesize that Mg absorption from some other seaweeds is not low because of the diversity of fibers. We measured Mg concentration and Mg solubility after in vitro digestion in edible seaweeds, Aosa (Ulvaceae pertusa), Kombu (Laminaria japonica) and Funori (Gloiopeltis furcata). Then we determined Mg absorption in rats given diets containing these seaweeds or magnesium oxide as the major source of Mg, and calculated Mg absorption from seaweeds.

RESULTS

The fractional apparent absorption of Mg in seaweeds was Kombu = magnesium oxide > Aosa = Funori. Mg concentration was Aosa > Kombu and Funori had an intermediate amount of Mg, while Mg solubility after in vitro digestion was Funori = Kombu > Aosa. Consequently, the absorbable Mg concentration was Aosa = Kombu > Funori.

CONCLUSION

The absorption of Mg from different seaweeds differs and is not affected by the Mg solubility alone. The absorbable Mg concentration was high in Aosa and in Kombu, indicating that Aosa and Kombu are good sources of Mg.

Yacon flour and Bifidobacterium longum modulate bone health in rats

Yacon flour has been considered a food with prebiotic potential because of the high levels of fructooligosaccharides, which allows for its use in formulating synbiotic foods. The purpose of this study was to evaluate the effect of yacon flour and probiotic (Bifidobacterium longum) on the modulation of variables related to bone health. Thirty-two Wistar rats were divided into 4 groups: control, yacon flour, diet+B. longum, and yacon flour+B. longum. After euthanasia, the bones were removed for analysis of biomechanical properties (thickness, length, and strength of fracture) and mineral content (Ca, Mg, and P); the cecum was removed for analysis of the microbiota and short-chain fatty acids. Tibia Ca, P, and Mg content was significantly (P<.05) higher in groups fed diet+B. longum, yacon flour+B. longum than in the control group. An increase in fracture strength was observed in the yacon flour (8.1%), diet+B. longum (8.6%), and yacon flour+B. longum (14.6%) in comparison to the control group. Total anaerobe and weight of the cecum were higher (P<.05) in rats consuming the yacon flour diet compared with the other groups. Cecal concentration of propionate was higher in all experimental groups compared with the control (P<.05). Yacon flour in combination with B. longum helped increase the concentration of minerals in bones, an important factor in the prevention of diseases such as osteoporosis.

Fiber fermentability effects on energy and macronutrient digestibility, fecal traits, postprandial metabolite responses, and colon histology of overweight cats

Considering the different potential benefits of divergent fiber ingredients, the effect of 3 fiber sources on energy and macronutrient digestibility, fermentation product formation, postprandial metabolite responses, and colon histology of overweight cats (Felis catus) fed kibble diets was compared. Twenty-four healthy adult cats were assigned in a complete randomized block design to 2 groups of 12 animals, and 3 animals from each group were fed 1 of 4 of the following kibble diets: control (CO; 11.5% dietary fiber), beet pulp (BP; 26% dietary fiber), wheat bran (WB; 24% dietary fiber), and sugarcane fiber (SF; 28% dietary fiber). Digestibility was measured by the total collection of feces. After 16 d of diet adaptation and an overnight period without food, blood glucose, cholesterol, and triglyceride postprandial responses were evaluated for 16 h after continued exposure to food. On d 20, colon biopsies of the cats were collected under general anesthesia. Fiber addition reduced food energy and nutrient digestibility. Of all the fiber sources, SF had the least dietary fiber digestibility (P < 0.05), causing the largest reduction of dietary energy digestibility (P < 0.05). The greater fermentability of BP resulted in reduced fecal DM and pH, greater fecal production [g/(cat × d); as-is], and greater fecal concentration of acetate, propionate, and lactate (P < 0.05). For most fecal variables, WB was intermediate between BP and SF, and SF was similar to the control diet except for an increased fecal DM and firmer feces production for the SF diet (P < 0.05). Postprandial evaluations indicated reduced mean glucose concentration and area under the glucose curve in cats fed the SF diet (P < 0.05). Colon mucosa thickness, crypt area, lamina propria area, goblet cell area, crypt mean size, and crypt in bifurcation did not vary among the diets. According to the fiber solubility and fermentation rates, fiber sources can induce different physiological responses in cats, reduce energy digestibility, and favor glucose metabolism (SF), or improve gut health (BP).

Prebióticos y su efecto en la biod sponibilidad del calcio

En la búsqueda de medidas de prevención de enfermedades crónicas no trasmisibles, se piensa en los prebióticos como una forma efectiva, saludable y relativamente barata para la optimización de la absorción de Ca. El aumento de la expectativa de vida de la población y el incremento de enfermedades como la osteoporosis traen graves consecuencias a la salud del individuo, acarreando importantes desembolsos económicos. En esta revisión se condensa el conocimiento presente sobre el efecto fisiológico del consumo de carbohidratos prebióticos y su posible interferencia en la biodisponibilidad del Ca, como también las posibilidades de su empleo en estrategias para combatir las deficiencias del mineral. Se elaboró una recopilación de los estudios originales realizados con mayor impacto en el tema, dando preferencia a los publicados en los últimos 6 años. Utilizamos las bases de datos PubMed, Lilacs e SciELO, usando las palabras claves calcio, prebióticos e probióticos.

Yacon syrup: beneficial effects on obesity and insulin resistance in humans

BACKGROUND & AIMS

Syrup obtained from yacon roots could be well positioned as a nutraceutical product due to its high fructooligosaccharides content. We examined the beneficial effects and tolerance of yacon syrup on human health.

METHODS

Obese and slightly dyslipidemic pre-menopausal women were studied over a 120-day period in a double-blind placebo-controlled experiment. We used two doses of yacon syrup, 0.29 g and 0.14 g fructooligosaccharides/kg/day. At the start and end of the study, anthropometric measurements, blood glucose, calcium, lipid and insulin concentrations and Homeostasis Model Assessment index were determined.

RESULTS

The recommended daily consumption of yacon syrup with no undesirable gastrointestinal effects is 0.14 g fructooligosaccharides/kg. Daily intake of yacon syrup produced a significant decrease in body weight, waist circumference and body mass index. Additionally, decrease in fasting serum insulin and Homeostasis Model Assessment index was observed. The consumption of yacon syrup increased defecation frequency and satiety sensation. Fasting glucose and serum lipids were not affected by syrup treatment and the only positive effect was found in serum LDL-cholesterol levels.

CONCLUSIONS

Yacon syrup is a good source of fructooligosaccharides and its long-term consumption produced beneficial health effects on obese pre-menopausal women with insulin resistance.