DETERMINACION DE AZUCARES REDUCTORES DNS PDF

Determinación de azúcares reductores en extractos de alga Undaria pinnatifida method (DNS) for the determination of reducing sugars in seaweed Undaria. Características metrológicas en la determinación de azúcares reductores para el control de la calidad en mezclas de oligogalacturónidos. Azucares Por Metodo DNS – Download as Word Doc .doc /.docx), PDF File .pdf ), Text File .txt) or read online.

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The invention relates to a strain Pichia kluyveri, with ability to ferment naturally orange juice, and their use in producing a low-alcohol beverage.

Alcoholic fermentation is perhaps the first bioprocess carried out by determinacikn. Although used as a method of preserving fruit at first, over the years was consolidated as a method for obtaining alcoholic beverages such as wine.

In general when speaking of drinks produced by fermentation of fruit juices referred to wine made from grape juice. Blackwell Scientific Publications, Oxford, England. Most of the wine is produced from grapes and, unless otherwise specified source, the word came to the product resulting from the fermentation of grape juice Brown et al relates. The dhs of wines other than grape fruits is very popular in many northern European countries, where climatic conditions hinder the development of the wine industry, especially in Poland, Russia and Germany.

In Britain only a small amount of other fruit wines is produced on a commercial scale, but it is very common homemade craft. Traditionally for the fermentation of musts different fruits populations existing yeast used in reductkres ecosystems in which the fruits are obtained.

During the fermentation process evolution of microbial populations in which a replace other, as the chemical composition of fermented medium is changing occurs.

In the case of fermentation of orange, the process presents a fundamental difference and an additional problem, over other musts from other fruits. The difference is that during the early stages of fermentation, Lactobacillus pushes all microorganisms, resulting in a strong accumulation of lactic acid, which gives the product a unpleasant odor and taste.

Applied and Environmental Microbiology, Specifically, Pichia is a genus of the family Saccharomycetaceae spherical, elliptical or oblong cells.

There are 91 species of the genus Pichia and specifically within the species P. Members of the genus Pichia are not able to ferment or digest lactose. As for the fermentation of other carbohydrates, it is variable according to species. En concreto, Pichia kluyveri es capaz de fermentar glucosa, pero no galactosa, sacarosa, maltosa, rafinosa y trehalosa. Specifically, Pichia kluyveri can ferment glucose but not galactose, sucrose, maltose, raffinose and trehalose.

Species of the genus Pichia, such as P.

ESA1 – Pichia strain kluyveri and applications. – Google Patents

There bibliographic record production of fermented citrus juices, dating back many years, such as Hendrickson and Kesterson Agric Exp Sta Bull In the latter case, it described that although these citrus juice can be made into wine flavor and pleasant aroma, adding sugar and carefully controlled processing conditions is required.

Braverman Composition and chemical technology Madrid Aguilar mentions and describes the steps for ‘wines citrus “, to which defined as products obtained by fermentation with wine yeast, juice from ripe fruits of varieties less acid, which sugar, in order to obtain wine more body and less acidic. The most updated scientific knowledge have on the development of citrus wines come from Turkey and other Asian countries China, Japan, Korea.

Among them, one can cite studies on the production of orange wine made by Arici-Oe et al. Food Sci Technol 29, Agric Life Sci 26, Also it described a process for obtaining a product derived from orange juice which implies a fermentation process by using alcoholic yeast ES In particular, the yeasts used belong to the genera Saccharomyces and Hanseniospora. In addition, also described a fermentation process of orange juice in the two yeast strains, which are added to orange juice are used sequentially.

Thus, although described some microorganisms with ferment capacity orange juice, there is a need to develop a process from which a beverage with improved organoleptic properties and lower alcohol is obtained.

The inventors have identified a yeast strain of the species Pichia kluyveri that has the capacity to carry out the fermentation of orange juice, resulting in a beverage derived from orange juice, with very good organoleptic properties for consumption, as a low alcohol content of about 2. Un cultivo de dicho aislado de P. A culture of said isolated from P.

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The presence of a suitable pulp concentration in orange juice source is advantageous, since it constitutes a reservoir of oxygen for yeast, it is necessary in the early stages of fermentation as well as provides a large amount of nutrients. Furthermore, the ability of the yeast strain of the invention to ferment only reducing sugars present in the juice, resulting in a final product containing non-reducing sugars such as sucrose, which makes its flavor very pleasant.

A culture or culture medium of said microorganism constitute further aspects of this invention.

Translation of “of dinitrosalicylic acid” in Spanish

In another aspect, the invention relates to the use of said microorganism or said culture to carry out alcoholic fermentation. In another aspect, the invention relates to a method of growth of said microorganism which comprises inoculating the said microorganism in a medium comprising orange juice.

In another aspect, the invention relates to a method for obtaining a product derived from orange juice comprising inoculation of said microorganism or a culture thereof in a culture medium comprising orange juice under conditions which allow the fermentation of reducing sugars orange juice.

In another aspect, the invention relates to a derivative of the orange juice product having an ethanol concentration of between 0. Figure 1 shows the evolution of the growth of the yeast strain 4N CECT in different media, representing time in days of growth versus the optical density measured at nm.

By fermentation, it means a catabolic process, completely anaerobic incomplete oxidation, in which the final product is an organic compound. As used herein, the term “reducing sugars or carbon hydrates” refers to those sugars having their carbonyl group functional group intact, and through it can react with other molecules.

These reducing sugars cause alteration of proteins by glycation reaction no enzyme also called Maillard reaction or glycation. In a particular embodiment, the microorganism of the invention, besides being able to ferment reducing sugars, no ability to ferment the nonreducing sugars. Tal como se observa en el Ejemplo 3, la cepa 4N de P.

As seen in Example 3, the strain 4N P. As used herein, the term “mutant” includes any individual or organism resulting from a mutation or genetic modification in the genome of said organism. Suitable methods for the determination of reducing sugars include calorimetric method of 3,5-dinitrosalicylic DNS Miller, GL In a preferred embodiment, the determination of reducing sugars is by 3- 5-dinitrosalicylic DNS. The microorganism of the invention can be grown in any suitable medium for yeasts.

Advantageously, said culture is grown under stirring. In another aspect, the invention relates to a culture medium of the microorganism of the invention comprising orange juice. This product has from 0.

Felipe Garcia –

The pH is about 3. Citric variety that can be used to produce the orange juice used as a culture medium include, but are not limited to, the following varieties: El origen del zumo de naranja para el cultivo del microorganismo de la The origin of orange juice for rexuctores the microorganism deerminacion the. In a particular embodiment, the orange juice is microbiologically stable.

To do this we proceed to pasteurization culture medium comprising orange juice.

ES2382843A1 – Pichia strain kluyveri and applications. – Google Patents

In a particular embodiment, if necessary, proceed to the correction of the culture medium, adding sugars or by changing the pH. Dicho medio de cultivo puede ser zumo de naranja puro o bien combinado con agua.

Said culture medium can be pure juice combined with water or orange.

The proportion of water and orange juice can be 1: It may also be a proportion in which there is more water than orange juice, such as 2: In another aspect, the invention relates to the use of the microorganism of the invention or the culture according to the invention to carry out the alcoholic fermentation. As described above, the term alcoholic fermentation is used to describe this fermentation process the microorganism of the invention processes carbohydrates to obtain as final products: In a particular embodiment of the invention the microorganism is capable of fermenting reducing sugars.

The inventors have revealed that the microorganism of the invention is capable of growing in a culture medium comprising orange juice in a similar way as it does in a rich medium so as YPD, as shown in Example 2 and in Figure 1. Thus, in one aspect, the invention relates to a method of growth of the microorganism of the invention or the culture of the invention, hereinafter first method of the invention, which comprises inoculating the said microorganism in a medium comprising orange juice.

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The first method of the invention comprises the step of inoculating the microorganism of the invention in a medium comprising orange juice. A skilled artisan widely known techniques inoculating a yeast in a culture medium. The culture conditions of the first method of the invention shall be determined by one skilled in the art and are also widely known for yeast.

Advantageously the microorganism of the invention is cultured with agitation at about rpm. The first method of the invention comprises the step of inoculating the microorganism of the invention, first a small scale and in small volume preinoculum and, after reaching sufficient biomass, transferring said microorganism to a larger scale culture.

Subsequently, after having achieved sufficient biomass in the preinoculum and said preinoculum is in exponential phase, it is transferred to the final medium larger scale culture comprising orange juice. The pre-inoculum can be added directly to the medium or culture final registration may be necessary to proceed to a centrifuge.

For the pre-inoculum has been grown in a different orange juice medium such as YPD, YPE or YPG is recommended to perform centrifugation and different washes, in order to remove most of the medium.

In a particular embodiment, the load culture inoculation is between 0. In a preferred embodiment, it said absorbance value is 0. This relationship is effective if the pre-inoculum is in exponential growth phase. The culture conditions in a medium comprising the orange juice determined by the expert in the art. Methods for determining whether the microorganism is growing properly in the medium comprising orange juice are those in which the cell biomass growth is determined before and after a suitable period of growth and said cell biomass before and after comparison.

For determination of the biomass, and thus know whether the growth method has gone well, one skilled in the art knows different methods exist, such as the determination of the optical density at nm of the culture in which it is growing the microorganism of the invention. In another aspect the invention relates to a method for obtaining a product derived from orange juice, hereinafter second method of the invention, which comprises inoculating the microorganism of the invention or the culture of the invention in a culture medium orange juice comprising, under conditions allowing fermentation of reducing sugars present in orange juice.

The method comprises several steps: Briefly, first a seed culture is grown at a temperature of 15 to 35, preferably 30 in a small volume to obtain sufficient biomass and subsequently to a larger volume of culture medium is transferred. Agitation during the fermentation process is performed continuously and in a range of 60 to rpm for the correct homogenization of the content, preferably said stirring is rpm.

The advantage of agitation during fermentation is homogenizing the physico-chemical and microbiological content in the fermenter. It is to be performed with minimal aeration of the fermentation broth to minimize the effects of oxygen on antioxidants or yeast metabolism.

Contact of antioxidants contained in the yeast with oxygen reduces the detterminacion nature of it. The effects produced oxygen contact yeast is the metabolic shift from fermentation metabolism of interest to respiratory metabolism no interest in this procedure.

In a particular embodiment, the microorganism of the invention may be combined with other yeasts also participate or assist in the fermentation, either sequentially or simultaneously inoculated. Such yeasts are yeasts known in the prior art that are able to ferment any sugar, both reducing and non-reducing sugars and are able to generate a final product with low alcohol content and good organoleptic properties.

The fermentation time is determined by one skilled in the art and is directly proportional to the concentration of fermentable sugars by the yeast in the medium and inversely proportional to temperature. Once the partial or total exhaustion of azkcares reducing sugars in the culture medium and the production of ethanol and other flavoring compounds takes place, the fermentation is terminated. The concentration of ethanol present in the fermented final product varies with the concentration of reducing sugars present in the starting juice, but ranges from 0.

Because a partial fermentation of sugars is experienced, adding sucrose as a sweetening is not necessary.