Wednesday, October 24, 2012

MASYAURA- A TRADITIONAL FOOD OF NEPAL


Masyaura is “Legume based traditional, non salted, partially fermented food product of Nepal. It is prepared mainly from Black Gram and Colocosia tuber by traditional sun drying as well as controlled fermentation and mechanical drying method”. Friable, brittle and spongy dried balls 2-5 cm in diameter, once it is prepared the dried balls are stored for future use. At the time of cooking, it is mixed with curry to make soup and served with rice as side dish.
Masyaura used by most of the vegetarians as a substitute for meat. It is usually prepared in cottage or home scale level and used as an adjunct in curry. It is also made from split black gram and vegetables like colocosia or radish or ash guard depending upon their availability. The quality of Masyaura depends upon effective sun drying, so is prepared during dry season. Spoilage can be result during rainy season. It is source of protein, carbohydrate and minerals. The protein quality of Masyaura is comparable to animal protein. The soluble proteins, non protein nitrogen, Vitamin B increases during drying whereas pH, starch, free sugar and reducing sugar contents are found to be decreased. During sun drying, total microbial load dominated by lactic acid bacteria, yeast leads to fermentation that increases the digestibility of proteins and starch, reduces the anti nutrients like oxalate, phytate etc. whereas the essential amino acid profile did not show any significant change. Hence better is the digestibility of final Masyaura. Sun drying is traditional method of preparation that takes 3-5 days depending on weather condition. So this links with preservation of vegetables by sun drying for long period.
For preparing masyaura, black gram and colocosia tuber are cleaned for removing foreign material. Black Gram is soaked overnight in clean, potable water and ground into thick paste using a wet grinder. Previously it was done by Dhiki and Janto. The colocosia tuber is washed, peeled and shredded into small pieces. The shreds are mixed with the paste of black gram dhal. The dough is made into small lumps and are placed 1 inch apart on bamboo trays (nanglo and mando) and sundried for until they become hard and dry.
While traditional method of preparation is still used in most part of the country, modern method of preparation is also in practice which is based on the use of inoculating micro-organism and rest of the process remains the same. Sun drying during preparation is the period of fermentation in masyaura.
Sun drying required longer duration is found to be more favorable for microbial growth (mainly lactic). The keeping quality depends on the microbial load in the preparation.
The fermentation of masyaura results significantly increase in vitamins, acidity, microbial load, soluble protein and digestibility of protein and starch whereas pH and starch content decreases. Increase in total acidity in the product also helps in enhancing the shelf life of the food. Although “controlled fermentation” method of preparation is practiced now, the traditional sun drying method is best for availability and nutritional point of view of masyaura.

Tuesday, October 23, 2012

β -GLUCAN - A FUNCTIONAL COMPONENT OF FOOD

β-Glucans are polysaccharides of D-glucose monomers linked by β-glycosidic bonds. They are found in cereals such as oat, barley, rye and wheat, mushroom and yeast cell walls having β (1→3), β (1→4) and β (1→6) glycosidic linkages. β-glucans are located throughout the starchy endosperm whereas in wheat the highest concentration is in the sub aleurone layer with little in the rest of the starchy endosperm. All 1, 3 configuration β glucans have the same biological potency whether they are derived from oats or yeast -the two major sources. These six-sided D-glucose rings can be connected to one another, on a variety of positions on the D-glucose ring structure. Some β-glucan compounds are continual repeats of D-glucose attached at a specific position. These unique carbohydrates often present unlike structures and contribute to dissimilar functions, which lead to disparate potential health benefits.
 β -glucans from oat, barley, and seaweed are primarily linear short β-(1, 3) segments with long β-(1, 4) branches. The forms from grains appear to function through a variety of mechanisms, such as reducing cholesterol reabsorption in the enterohepatic recirculation process, delaying absorption of dietary fat, and possibly enhancing intestinal fermentation by the microflora. As immune modulatory food ingredients, β-glucans are either soluble gel-forming components or insoluble particulates. These properties vary with the source and modification or degree of branching.
Sources of β Glucans:
Natural β -glucans are dietary supplement found in several common foods, including oats, barley, medicinal mushrooms  and organisms such as yeast, various fungi and in rye and wheat in lesser extent. It is located mainly in sub-aleurone, aleurone and bran parts of the grains. The richest concentrated source of β glucans is baker’s yeast cell wall. The major sources and its type are given as;
Oat: Oats possess high amounts of β-glucan in the form of soluble fiber, which helps lower cholesterol. This slows down the release of sugars into the bloodstream and extends the feeling of satiety after eating. Oat-derived β -glucan is linked to lower blood sugar and insulin levels in people with diabetes.
Barley: Barley β -glucan works by converting into a water-soluble gel, which facilitates the absorption of nutrients in the intestines while slowing digestion and trapping fats and carbohydrates. The feeling of fullness that results from slower digestion promotes diet control and weight loss by curbing hunger. 
Mushroom and Yeast: Mushroom and yeast β-glucan has the effect of aiding in the body's natural immune defenses by acting as an immune modulator. Two of the most common sources of these types of β-glucan are shitake mushrooms and Baker's yeast. Shitake-derived β -glucan blocked the progression of cancer cells; fight off infection naturally in the body. Yeast-derived β-glucan acts similarly to support the immune system. 
Functions of β Glucans:
β-glucans play a key role in some health-promoting properties, such as enhancement of immune function, protection against radiation exposure, cancer prevention and reduction of blood cholesterol and blood glucose levels. This also possesses several beneficial qualities, including the ability to fight off free radicals in a similar way to antioxidants.
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