Be focus on Oyster Sauce

Be Focus on Oyster Sauce

   

 

 Figure 1 Oyster sauce

Source: https://jet.com/product/Lee-Kum-Kee-Panda-Oyster-Sauce-18-oz/9be8b11ede2146feb95249e050ad1913

“Sauces have been around for centuries. During Roman times, sauces were used to hide the flavour and taste of meat . Can you imagine that what would Chinese cuisine be without oyster sauce? Today, we are discovering about the fact of oyster sauce!”

   

History of Oyster Sauce

      Oyster Sauce is a major condiment in Chinese cooking. It was invented only a hundred years ago, yet it has profoundly influenced Cantonese culinary culture, brought about a myriad of versatile dishes, and become an essential food seasoning in our daily life. Lee Kum Sheung is the inventor of oyster sauce who opened a tiny eatery and made his living selling cooked oysters. One day, he was cooking oyster as usual, but he lost track of time. Lee left them to simmer until he smelt a strong aroma. He noticed that the normally clear oyster soup had turned into a thick, brownish sauce with the most fragrant smell and unique, delicious taste which he started to sell, turning out to be very popular. Hence, he formed Lee Kum Kee and mass produced oyster sauce for sales in year 1888.

     
     Oyster sauces are well known for its magic of “bringing out the umami taste in flavourful foods” while “adding flavour to bland ingredients”, serving as versatile condiment ideal for umami-inducing, flavour enhancement, colour-enriching, brightness-adding and sauce-retaining for different cuisines. For example, it contains an umami flavor with a strong resemblance to seafood.

                                                        

History of Oyster Sauce

Source: Youtube channel

The Main Ingredient of Oyster Sauce?

                            

                                               Figure 2 Oyster 
 Source: http://hungrynaturalist.blogspot.my/2014/08/vol-4-no-9-homemade-oyster-sauce.html

           The answer of course is OYSTER!!!!!!!!!!!!!!!!!

How oyster sauce is made???

         
      In the past, oyster sauce is made by slowly simmering oysters in water until the juices caramelize into a brown, thick and intensely flavorful sauce. Today, most oyster sauce is made from salt, sugar, water and then thickened with modified cornstarch into the viscous dark brown condiment. This basic sauce can be flavoured with oyster extract and flavor enhancer (E261) to strengthen the flavor. Enhancer E261 is considered as MSG Monosodium Glutamate as an additive to be used in the preparation of oyster sayce. The sauce is coloured with caramel coloring (E150) in order to give oyster sauce black and brown colour. Oyster sauce can also be fermented into a fermented oyster sauce that has a nice balance between sweet and salty with a rich, earthy undertone.
    
      The serving size of oyster sauce is approximately 1 tablespoon and only 1/4 cup is typically added during cooking. Oyster sauce contains only 9 calories per serving size that allows addition of flavor to dishes without increasing the calories too much. Oyster sauce contains mainly carbohydrates at approximately 2.0 g per serving size. It also contains proteins and fiber at approximately 0.24, and 0.1 g per serving size, respectively. Oyster sauce contains no cholesterol and insignificant amounts of fat. The only mineral found in any appreciable quantity in oyster sauce is sodium. Sodium is found at 492 mg per serving size, which is about 20.5% of the Percent Daily Value (%DV).

What would be present in fermented oyster sauce???

         Angiotensin I converting enzyme (ACE) inhibitor can be isolated from fermented oyster sauce. It can help to reduce hypertension. Moreover, Angiotensin I converting enzyme (ACE) inhibitors, such as capto-pril, enalapril, alacepril and lisinopril are currently used extensively in the treatment of essential hypertension and heart failure in humans.

Physical and Biochemical Changes during Manufacturing of Oyster Sauce

          
       Proteins play an important role in the production of oyster sauce. Protein contents increases during the fermentation process of oyster sauce. Proteolysis is carried out during fermentation. In fact, fermented oyster sauce contained high amounts of glutamic acid, glycine, alanine, lysine and aspartic acid. However, different fermentation periods changes the amino acid composition of fermented oyster sauce by increasing the aspartic acid, leucine and isoleucine, but decreasing the glycine, proline and lysine content. Fermentation periods of oyster sauce usually last for 6 months. By comparing the contents of the essential amino acids in the fermented oyster sauce, lysine is found to be the most abundant in the first 2 months of fermentation process. At the end of 6 months’ fermentation, the contents of leucine, isoleucine and phenylalanine increase, whereas the content of lysine decreases. Besides, the major free amino acids found in fermented oyster sauce such as taurine, glutamic aicd, glycine, leucine, alanine and lysin increase throughout the whole fermentation period.

                                

Figure 3 Modified cornstarch function as thickening agent     Source: https://icdbiochem.en.made-in-china.com/offer/CoWmRAZYvtpG/Sell -Modified-Corn-Starch.

Modified cornstarch act as thickening agent in the production of oyster sauce. In the presence of water and heat, starch granules swell by absorbing water. As the water heat up, its molecules begin to move around very rapidly and bump into the starch granules, strong enough to disrupting the structure of the starch molecules. The starch molecules hydrate by trapping water  molecules causing the starch granules to swell and press up againsts each other in the sauce. As more heat is applied, the starch granules eventually begin to leak, freeing the starch molecule strands. At that point, the liberated starch strands are free to interact with each other and trap more water molecules to form network in a process known as gelling or gelatinization. The thickening of the oyster sauce at the end of the process increase its viscosity.

        Caramel colour of the oyster sauce is developed by adding of the caramel coloring (E150). Food-grade alkalis, acids and also salts may be used in amounts consistent with Good Manufacturing Practices in order to promote caramelization. Hence, it can produce greater colour intensity. In the manufacturing of oyster sauce, Class III which is Ammonia Caramel reagents (E150C) represents the major type of caramel colors used at about 80% of caramel production. This is because of their aromatic and colorant characteristics. The use of caramel coloring gives a black and brown colour to the oyster sauce.

Tips about oyster sauce

Take notes that after opening of the bottle of oyster sauce, the quality of the oyster sauce will decline over time with the color getting darker and the flavor getting stronger due to the oxidation process. Thus, peak flavor for oyster sauce is when it is first opened. The first indication that oyster sauce is going bad is usually a separation of liquid from the other ingredients.

Last but not least, ACE-inhibitory properties found in oyster sauce are gaining much more importance for treating hypertension. Hence, be focus on oyster sauce since it is not just a condiment, but it can be a functional food due to its health benefits!

References

            1. C. Cunha, L. Senra, J.O. Fernades, S. C. Cunha. (2014). Gas Chromatography –   Mass Spectrometry Analysis of 4-Methylimida. Food Analytical Method, 1519-1525.

            2. J.Y. Je, P.J. Park, W.J. Jung, S.K. Kim. (2005). Amino acid changes in fermented oyster sauce with different periods. Food Chemistry, 15-18.

            3.Rail, K. (2017). Nutritional Value of Fried Oysters.  Assessed on 24th April 2018 from: https://www.livestrong.com/article/545292-how-to-cook-oysters-on-the-stove/.e/.