The white stuff in Chinese food is cornstarch, which is used to thicken the sauces for a glossy and velvety texture.
Sometimes MSG or monosodium glutamate is used for a flavor enhancer which can result in white stuff in Chinese food and sometimes even baking soda t is used for tenderizing meat.
Some Chinese foods also contain water chestnuts or even decorative elements like rice or lemon zest under the Chinese dish.
But most commonly the white stuff in Chinese food is a result of thickening agents like the cornstarch or flavorings in the sauce
The mother sauce of Chinese food is Soy sauce as well as aromatic oil mixtures like ginger oil and scallion as well as regional aster sauces like Sichuan's Doubanjiang or even traditional Lu Shui sauce, which serves as foundational elements, and often thickened with starch (Qian or gourouquian to form various final sauces.
Soy sauce is the quintessential savory base for countless Chinese dishes, which provide a nice umami flavor.
Aromatic oils that are infused with ginger, garlic and scallions also form fragrant bases for Chinese stir fries and sauces.
Qian is a thickening technique that uses cornstarch or flour slurry mixture with liquid to create glossy and thickened sauces, which are common in dishes like Moo Goo Gai Pan.
Lu Shui is a master sauce and is complex and long simmered which is often soy based with spices.
Doubanjiang (Sichuan) is fermented broad bean paste and is considered a mother ingredient for spicy Sichuan cuisine.
Chinese food chefs also sometimes create versatile stir fry sauces like soy sauce, oyster sauce, sesame oil, sugar etc for home cooking.
The brown sauce they use in Chinese food is a savory, glossy and thickened sauce that is made from soy sauce, beef/chicken broth, oyster sauce, sugar, Shaoxing wine, as well as some aromatic ingredients like ginger and garlic.
The brown sauce in Chinese food is also thickened with a cornstarch slurry o create a nice rich gravy, for meat dishes like beef and broccoli and even stir fries.
The Chinese brown sauce is also common in American Chinese takeout.
The other sauces that they use at Chinese restaurants includes a variety of sauces like soy sauce, sweet and sour sauce, hot mustard, hoisin sauce, oyster sauce, black bean sauce, chili garlic sauce and even Duck Sauce also known as plum sauce as well chili oil sauce.
Chili oil sauce is infused with chili peppers, which offers heat and aroma like Lao Gan Ma, Chili Garlic Sauce.
Hot mustard is pungent and fiery, is a classic for fried appetizers.
Plum sauce and duck sauce is fruity, sweet and spicy and is great with egg roles.
Sweet and sour sauce is tangy and sweet and is perfect for fried dishes like pork and chicken.
Soy sauce is a sauce with a ubiquitous savory base, often mixed with vinegar, ginger or chili oil.
The orange sauce in Chinese food is called Duck Sauce, which is a sweet, fruity like jelly condiment sauce for dipping fried foods.
Another variation of duck sauce is orange sauce as Panda Express for example, which is a tangy and citrusy sauce that is used for saucing crispy chicken, shrimp or vegetables and is made with orange juice, soy sauce, vinegar, sugar and ginger as well as garlic.
Duck sauce is more of a sweet and sour dip, and orange sauce is a glaze and coating.
The red sauce you get with Chinese food is often sweet and sour sauce that is found American Chinese restaurants, which is a vibrant, tangy and sweet condiment which is made from tomato paste or ketchup, sugar, vinegar and pineapple juice that is also thickened with cornstarch.
The red sweet and sour sauce is often used for dipping spring rolls, egg rolls and even fried foods.
Although there's also other Chinese red sauces that you get with Chinese food which include Sichuan chili oil that is often with fermented beans and even some other sauces.
The red Chinese sauces are commonly called spicy Sichuan Chili Oil and sometimes sweet and sour Chinese Red Sauce.
The spicy Sichuan Chili Oil red sauce is a tangy, sweet and sour sauce also known as Hong You.
Spicy Sichuan Chili Oil is a fiery, aromatic oil that is infused with chili flakes, Sichuan peppercorns, and spices and is used as a condiment or cooking base.
Other red Chinese sauces are Doubanjiang also known as spicy red bean paste, sweet chili sauce and Cuihong red hot chili sauce.
Sweet and sour Chinese red sauce is a classic Chinese takeout staple, which is usually red or pink and combines sugar, vinegar as well as often ketchup or pineapple juice for sweetness and tang.
Doubanjiang spicy bean paste is a fermented bean paste with chilies, which provide deep, savory heat, often used in Sichuan dishes like Mapo Tofu.
Sweet chili sauce is a sauce that has a balance of sweet and spicy, which often is made with red chilies, vinegar, sugar, and garlic and is popular as a dip.
Cuihong red hot chili sauce is a specific brand of Chinese red sauce that is known for being spicy, fragrant, and addictive, with ingredients like garlic, chili powder and Sichuan pepper.
Another Chinese reddish sauce is Yuxiang "fish fragrant" sauce, which is a Sichuan sauce with dried chilies, Sichuan peppercorns and hot bean paste, which gives it a complex, spicy sweet and sour flavor.