In Vitro Antimicrobial Activity of Stevia Rebaudiana Bertoni Leaves

Purpose: The aim of the present study was to investigate antimicrobial activity of the various extracts of Stevia rebaudiana leaves. Method: Stevia rebaudiana Bertoni leaves were extracted in water, methanol, ethyl acetate and hexane and their antimicrobial activities were examined against few selected microorganisms including B. subtilis, S. aureus, M. luteus, S. marcenscens, P. aeruginosa, B. megaterium, E. coli, P. vulgaris, Yeast, A. niger and R. oligoporus using cup plate method. Results: Water extract of Stevia leaf showed activity against B. subtilis and S. aureus only. Methanol extract gave the highest zone of inhibition against P. aeruginosa whereas minimum zone of inhibition was found against S. aureus and yeast. B. megaterium and yeast were found to be highly susceptible towards ethyl acetate and hexane extracts, respectively whereas A. niger and B. subtilis were found to be least susceptible against ethyl acetate and hexane extracts, respectively. Hexane extract showed the highest activity against yeast among the tested microorganisms. Conclusion: The study confirms the possible antimicrobial potentiality of the leaf extract of Stevia rebaudiana. Keywords: Stevia rebaudiana, antimicrobial activity, leaf extracts > Tropical Journal of Pharmaceutical Research Vol. 5 (1) 2006: pp. 557-56

Stevia Rebaudiana, Oligofructose and Isomaltulose as sugar replacers in marshmallows stability and antioxidant properties

[EN] Consumers are increasingly demanding products with natural ingredients and functional properties. The replacement of conventional sugars with recently available sugars or sweeteners could result in the perception of candies as healthier products. Therefore, the objective of this work was to evaluate the influence of isomaltulose, oligofructose and stevia extracts on the physicochemical, mechanical, optical and antioxidant properties as well as the shelf life of marshmallows. A sensory test was carried out in order to evaluate the influence of these ingredients on the acceptance of this product. The instrumental and sensorial textural results indicate that the sucrose and glucose syrup in commercial marshmallows could be replaced by a mixture of isomaltulose, oligofructose and stevia. Adults found the new and the traditional marshmallows to be very similar. However, children only found similarities in terms of the texture. These new marshmallows, besides being more microbiologically stable, have added value due to their antioxidant properties. Practical ApplicationsSociety is becoming increasingly aware of the importance of nutrition in health, and this has a decisive impact on the proposals of the candy sector in terms of innovation and new product development. The main trends of the market are focused on eliminating the unhealthy ingredients in the formulations, such as sugars, and even incorporate active ingredients with functional properties, but without forgetting customer satisfaction. At present, the industry is using both intense and volume artificial sweeteners as conventional sugar substitutes. However, the food industry now has the possibility of using alternative natural sweeteners such as stevia, oligofructose and isomaltulose, with the added value of providing certain healthy benefits. The results of the present study could provide pertinent information to the confectionary industry that wishes to take on the challenge of developing candies with functional ingredients.The authors thank the Universitat Politecnica de Valencia (Spain) (for funding the project PAID 2011-ref: 2012 and the PhD scholarship), and the Generalitat Valenciana (Spain) (for the project GV/2013/029).Periche Santamaría, A.; Castelló Gómez, ML.; Heredia Gutiérrez, AB.; Escriche Roberto, MI. (2016). Stevia Rebaudiana, Oligofructose and Isomaltulose as sugar replacers in marshmallows stability and antioxidant properties. Journal of Food Processing and Preservation. 40:724-732. https://doi.org/10.1111/jfpp.12653S72473240Barba, F. J., Grimi, N., & Vorobiev, E. (2015). Evaluating the potential of cell disruption technologies for green selective extraction of antioxidant compounds from Stevia rebaudiana Bertoni leaves. Journal of Food Engineering, 149, 222-228. doi:10.1016/j.jfoodeng.2014.10.028Barba, F. J., Criado, M. N., Belda-Galbis, C. M., Esteve, M. J., & Rodrigo, D. (2014). Stevia rebaudiana Bertoni as a natural antioxidant/antimicrobial for high pressure processed fruit extract: Processing parameter optimization. Food Chemistry, 148, 261-267. doi:10.1016/j.foodchem.2013.10.048Belda-Galbis, C. M., Pina-Pérez, M. C., Espinosa, J., Marco-Celdrán, A., Martínez, A., & Rodrigo, D. (2014). Use of the modified Gompertz equation to assess the Stevia rebaudiana Bertoni antilisterial kinetics. Food Microbiology, 38, 56-61. doi:10.1016/j.fm.2013.08.009Campbell, G. (1999). Creation and characterisation of aerated food products. Trends in Food Science & Technology, 10(9), 283-296. doi:10.1016/s0924-2244(00)00008-xCarbonell-Capella, J. M., Barba, F. J., Esteve, M. J., & Frígola, A. (2013). High pressure processing of fruit juice mixture sweetened with Stevia rebaudiana Bertoni: Optimal retention of physical and nutritional quality. Innovative Food Science & Emerging Technologies, 18, 48-56. doi:10.1016/j.ifset.2013.01.011Chatsudthipong, V., & Muanprasat, C. (2009). Stevioside and related compounds: Therapeutic benefits beyond sweetness. Pharmacology & Therapeutics, 121(1), 41-54. doi:10.1016/j.pharmthera.2008.09.007(2011). Revised exposure assessment for steviol glycosides for the proposed uses as a food additive. EFSA Journal, 9(1), 1972. doi:10.2903/j.efsa.2011.1972Franck, A. (2002). Technological functionality of inulin and oligofructose. British Journal of Nutrition, 87(S2), S287-S291. doi:10.1079/bjn/2002550Gong, Q., & Bell, L. N. (2013). Degradation kinetics of rebaudioside A in various buffer solutions. International Journal of Food Science & Technology, 48(12), 2500-2505. doi:10.1111/ijfs.12241Kawai, K., Yoshikawa, H., Murayama, Y., Okuda, Y., & Yamashita, K. (1989). Usefulness of Palatinose as a Caloric Sweetener for Diabetic Patients. Hormone and Metabolic Research, 21(06), 338-340. doi:10.1055/s-2007-1009230ISO 5492 2008 Sensory analysis. Vocabulary. International Organization for StandardizationISO 8589 2007 Sensory analysis. General guidance for the design of test roomsKALETUNC, G., NORMAND, M. D., JOHNSON, E. A., & PELEG, M. (1992). INSTRUMENTAL DETERMINATION OF ELASTICITY OF MARSHMALLOW. Journal of Texture Studies, 23(1), 47-56. doi:10.1111/j.1745-4603.1992.tb00510.xLemus-Mondaca, R., Vega-Gálvez, A., Zura-Bravo, L., & Ah-Hen, K. (2012). Stevia rebaudiana Bertoni, source of a high-potency natural sweetener: A comprehensive review on the biochemical, nutritional and functional aspects. Food Chemistry, 132(3), 1121-1132. doi:10.1016/j.foodchem.2011.11.140Lina, B. A. R., Jonker, D., & Kozianowski, G. (2002). Isomaltulose (Palatinose®): a review of biological and toxicological studies. Food and Chemical Toxicology, 40(10), 1375-1381. doi:10.1016/s0278-6915(02)00105-9Muanda, F. N., Soulimani, R., Diop, B., & Dicko, A. (2011). Study on chemical composition and biological activities of essential oil and extracts from Stevia rebaudiana Bertoni leaves. LWT - Food Science and Technology, 44(9), 1865-1872. doi:10.1016/j.lwt.2010.12.002Periche, A., Koutsidis, G., & Escriche, I. (2013). Composition of Antioxidants and Amino Acids in Stevia Leaf Infusions. Plant Foods for Human Nutrition, 69(1), 1-7. doi:10.1007/s11130-013-0398-1Periche, A., Heredia, A., Escriche, I., Andrés, A., & Castelló, M. L. (2015). Potential use of isomaltulose to produce healthier marshmallows. LWT - Food Science and Technology, 62(1), 605-612. doi:10.1016/j.lwt.2014.12.024Sanz, T., Salvador, A., Baixauli, R., & Fiszman, S. M. (2009). Evaluation of four types of resistant starch in muffins. II. Effects in texture, colour and consumer response. European Food Research and Technology, 229(2), 197-204. doi:10.1007/s00217-009-1040-1Shahidi, F., Liyana-Pathirana, C. M., & Wall, D. S. (2006). Antioxidant activity of white and black sesame seeds and their hull fractions. Food Chemistry, 99(3), 478-483. doi:10.1016/j.foodchem.2005.08.009Shukla, S., Mehta, A., Mehta, P., & Bajpai, V. K. (2012). Antioxidant ability and total phenolic content of aqueous leaf extract of Stevia rebaudiana Bert. Experimental and Toxicologic Pathology, 64(7-8), 807-811. doi:10.1016/j.etp.2011.02.002Sivaram, L., & Mukundan, U. (2003). In vitro culture studies on Stevia rebaudiana. In Vitro Cellular & Developmental Biology - Plant, 39(5), 520-523. doi:10.1079/ivp2003438Struck, S., Jaros, D., Brennan, C. S., & Rohm, H. (2014). Sugar replacement in sweetened bakery goods. International Journal of Food Science & Technology, 49(9), 1963-1976. doi:10.1111/ijfs.12617Tadhani, M. B., Patel, V. H., & Subhash, R. (2007). In vitro antioxidant activities of Stevia rebaudiana leaves and callus. Journal of Food Composition and Analysis, 20(3-4), 323-329. doi:10.1016/j.jfca.2006.08.004Tan, J. M., & Lim, M. H. (2008). Effects of gelatine type and concentration on the shelf-life stability and quality of marshmallows. International Journal of Food Science & Technology, 43(9), 1699-1704. doi:10.1111/j.1365-2621.2008.01756.xVarzakas, T., & Labropoulos, A. (2012). Other Sweeteners. Sweeteners, 175-208. doi:10.1201/b12065-8Vasiljevic, T., & Varzakas, T. (2012). Bulking and Fat-Replacing Agents. Sweeteners, 395-418. doi:10.1201/b12065-1

Antioxidant and antimicrobial effects of stevia (Stevia rebaudiana Bert.) extracts during preservation of refrigerated salmon paste

Stevia (Stevia rebaudiana Bert.) is a relevant source of natural phenolic compounds with antioxidant and antimicrobial properties. The aim of this study was to evaluate the potential protective effect of crude stevia extracts on the quality and shelf-life of salmon (Salmo salar) paste. For this, polyphenol extracts obtained by water extraction, ethanol/water extraction and supercritical CO2 with ethanol extraction were evaluated in preserving salmon paste. Salmon paste was stored under refrigerated conditions (5 degrees C) for 21 days, being primary, secondary, and total lipid oxidations monitored along storage by means of peroxide, p-anisidine, and TOTOX indices, respectively. In addition, 3/6 ratio, polyene index, and -tocopherol were monitored. Microbiological analysis comprised the investigation of aerobic mesophiles and psychrotrophes. Salmon paste samples treated with ethanol/water and supercritical CO2-ethanol stevia extracts exhibited the highest (p<0.05) 3/6 ratio and -tocopherol content. Besides, partial inhibition of both primary and secondary lipid oxidation events and aerobes and psychrotroph growth was also observed in both samples. These results correlated with the fact that ethanol/water and supercritical CO2-ethanol extracts provided the highest DPPH and FRAP values. These results open the way to the utilization of bioactive compounds from stevia leaves for the preservation of foods derived from salmon. Practical applications: The results obtained in this research show the possibility of using stevia and/or its derivatives of the sweetener industry as an alternative source of natural antioxidants in refrigerated fatty fish paste. The results indicate that it is possible to obtain advantages in the refrigerated salmon paste, based on the use of some extracts of stevia, which can help to inhibit lipid oxidation and development of pathogenic microorganisms. Further studies on the use of stevia and its derivatives should focus on the application of clean separation technologies such as supercritical fluid extraction. Stevia extracts obtained by extraction with water (W), ethanol-water mixture (E/W, 50:50 v/v) and extraction with supercritical CO2 and ethanol (SCE; scCO(2)/E, 95: 5 v/v) previously elimination of the steviosides demonstrates a conservative effect of refrigerated salmon paste. The SCE and E/W extracts provides better control of primary and secondary lipid oxidation compounds and moderate inhibition of aerobes and psychrotrophs.Innova Project 11CEII-9568 Fondecyt Regular 112031