Monday, January 9, 2012


Hummus is a chick pea based product with wide international popularity and interestingly it is a relatively stable product with reasonable shelf life. high Pressure Processing Technology (HPP), Chemical preservatives like citric acid, benzoate, pasteurization, hot fill, Tetrapack are all suitable for extending shelf life of this product for a few days. Though it is claimed to be an Arab preparation used by the people in the Middle East for centuries as a dip, this is hotly contested by the Jews who consider it their ethnic food. Interestingly Jews are reported to be consuming double the quantity of Hummus as compared to that by the Arab population. Who ever is responsible for the birth of Hummus, the fact remains that it is a ell established dip or spread product through out the world. Major ingredients in preparing a good authentic Hummus include cooked and mashed chick pea, blended Tahini, Olive oil, lemon juice and garlic. There are dozens of variations evolved over the last few decades to suit the palates of different segments of population. 

Nutritionally it is a well balanced food adjunct containing 166 kC of energy per 100 gm, 14.3% carbohydrate, 9.6% fat and 7.9% proteins. Besides it is also a significant source of iron, Vitamin C, Folates and Pyridoxine. Since it contains solids derived from Sesame, its Methionine content gives a high protein efficiency value to the product while its monounsaturated fat content further boosts up its nutritive value. no wonder Hummus is a $ 300 million business in the US and growing fast among the ethnic foods. One of the variations of Hummus contains coriander making it distinctly Indian reminding many about the chutney preparations in South India, used as an adjunct for ethnic foods like Idli, Dosa, Vada etc. The product is highly perishable with hardly a couple of days shelf life under ambient conditions. It is further known that the life can be extended in the refrigerator up to 7 days while it can last up to 2 months in a freezer chest. Also reported is its ability to stay long if pasteurized and stored at 4C up to 3-18 months. Tetrapack technology claims that the product can be preserved for months if properly processed. Same is true with High Pressure Processing Technology which is recommended for long term storage of Hummus.

According to some experts if packed Hummus is unopened, some pasteurized Hummus brands keep well for periods up to 18 months!. In general, pasteurized brands are known to keep well for 2-3 months. The differences in shelf life between brands can be attributed to variations in the recipe as well as pasteurization methods. While Citric acid and salt are preferred natural preservatives, artificial preservatives like sodium benzoate and potassium sorbate find extensive use by the industry. A growing number of pasteurized Hummus brands are shelf stable and do not require refrigeration. Brands that contain preservatives are safe for up to 60 days while those without preservatives are often marketed as natural or organic, provided they adhere to the standards  required for such labeling. Preservative-free Hummus brands must be stored under refrigerated conditions for good shelf life. Some processors of unpasteurized foods contend that pasteurization destroys nutrients and this is true with any food processing when there is lowering of nutritive vale to some extent. After all processing is based on the concept that there is a trade of between nutritive value and convenience. Because Hummus is marketed as a healthful snack it is natural to expect most brands claiming they are free from artificial preservatives.

Chutneys in South India are many in varieties but commonly they suffer from microbial spoilage, rancidity, staling, discoloration etc and they have never been standardized to the extent that any single product can be said to represent typical home made product in traditional homes in Karnataka, Andhra Pradesh and Tamilnadu. While scientific work on Chutneys is far and few, its popularity is such that most people find it difficult to eat traditional break fast foods without this ubiquitous adjunct. Why Indian Food Scientists have not looked at the preservation technology used by the Hummus industry is really baffling. The similarities between Hummus and Chutney are so much that even in the profile of ingredients used there is some commonality. These preparations have a protein source, a fat source, a spice source, a sourant or a pH modifier and salt. In Chutney coconut serves as a source of fat as well as protein while the sourant may be tamarind, amchur or lime juice. The spice component in Hummus is Garlic while in Chutney it is Chilli. 

The above comparison makes it clear that whatever technologies are used by the Hummus industry can be effective in preserving Chutneys also without any major change. Of course the vulnerability of coconut oil to hydrolytic rancidity is a problem that needs to be tackled. Probably roasting the coconut gratings sufficiently to inactivate lipase enzyme may retard such rancidity. Pasteurization, use of preservatives, Tetrapack technology, HPP Technology, Gamma irradiation, Hurdle technology all may work in getting reasonable extension of shelf life for Indian chutneys. Food industry must put pressure on Public R & D institutions in the country to take up some basic work as well as evolving preservation commercial processes by giving priority it deserves.


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