Definition of Spices

Spice refers to the specific parts of plants that have taste attributes such as natural flavor or odor and can be used as edible seasonings or condiments, and it is an abbreviation for a class of edible plant spices that can make food present aroma, pungency, numbness, spiciness, bitterness, sweetness, and other characteristic odors. In a nutshell, it is a seasoning that has both a certain aroma and a certain taste [1]. Spices are commodities composed of dozens of aroma and function of unique plant-based raw materials, which comes from the roots, stems, leaves, buds, seeds of plants [2].

I. Characteristic aroma components in spices
Various kinds of spices have different aroma, is due to the different and more or less contained aroma components. The effect of aroma-enabling spices mainly comes from the aromatic components in them, mostly composed of dozens or even hundreds of compounds. The more prominent aroma components are pinene, linalool, gingerol, cinnamaldehyde, eugenol and so on. The aroma components in the spices are mainly the following 4 types of compounds.

Second, aliphatic compounds
Aliphatic compounds are widely found in natural spices, such as in green leafy plants containing leaf alcohol, that is, cis-3-hexenol, with grassy fragrance; rue oil contains rue ketone, that is, methyl nonyl ketone.

Third, aromatic compounds
Aromatic compounds are also quite widespread in natural spices, such as eugenol in clove oil; thymol in thyme oil; aniseed brain in fennel oil; cinnamon aldehyde in cinnamon oil; and vanillin in vanillin.

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IV. Terpenes
Terpenes often constitute the main components of various spice oils, such as menthol in peppermint oil; eucalyptus oleoresin in eucalyptus oil accounts for about 70%, etc. Terpene hydrocarbons: laurolene, basilene, limonene, gingerene, α-pinene, β-pinene, α-juniperene, α-acacacia alkene, and so on. Terpene alcohols: nerol, geraniol, citronellol, linalool, thin aldehyde, perillaldehyde, etc.

Terpene aldehydes: citronellal, citronellal, hydroxycitronellal, watercress aldehyde, perilla aldehyde, etc.

Terpene ketones: menthone, piperone, camphor, etc. Terpene esters: menthyl acetate, citronella acetate, geranyl acetate, etc..

Fifth, nitrogen-containing, sulfur-containing compounds
These compounds exist in the natural spices but the content is very small. Spices containing propyl sulfide or allyl sulfide chemical structure of the components generally have onion, garlic flavor. Representative spice ingredients include diallyl disulfide, allyl mercaptan, methacryl disulfide, methyl propyl disulfide, propenyl, propyl disulfide and so on.

Physiological role of spices

The role of spices in flavoring is mainly through the stimulation of taste, smell, vision, pain and temperature perception and other nervous systems, to improve and strengthen the aroma and taste of food, enhance the role of human appetite. Spices have many functions, including the enhancement of food color, aroma and taste, so that the originally monotonous taste into an easily acceptable taste.

When people judge the deliciousness of food, they generally do so on the basis of five senses: first, the visual perception of color; second, the olfactory capture of smell; third, the taste perception of flavor; fourth, the pain sense of the degree of stimulation to withstand; and fifth, the tactile sense of the physical nature of the food (softness, hardness, temperature). Spices have a very important influence on all five of these senses, but the most influential are the senses of sight, smell, pain and temperature.

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I. Visual Influence
Spices such as the red of bell peppers, turmeric yellow, saffron dark red, etc. have a very bright color, will be used in food cooking can be obtained directly after the color effect, to promote appetite has an obvious effect.

Second, the olfactory influence
The smell of spices can cause pleasure to the human sense of smell, has been found to have more than 400,000 kinds. Part of these spices applied to cooking, will make the food produce a certain flavor.

The central mechanism of food intake, which is related to the production of appetite, consists of two main parts: the lower lateral part of the optic bed in the brain (feeding center, LHA) and the lower ventral medial nucleus of the optic bed (satiety center, VMH), i.e., it is regulated by the opposing effects of these two centers. There are many factors that can influence the strength of appetite in humans and animals, but the first thing an organism relies on in the process of determining the palatability of a substance and the generation of appetite is the sense of smell. After the sense of smell captures the odor information of spices, it is transmitted to the lower part of the optic bed of the brain through the central nervous system for total processing, and the high-level joint control mechanism formed by the lower part of the optic bed of the brain and the proximal system reprocesses the olfactory information, and ultimately forms the “appetite” or the specific “ingestion” action. The final “appetitive” or specific “ingestive” action is formed. Spice odors have a strong stimulatory effect on the central nervous system, including the cerebral cortex.

Nociceptive Effects

Most spices have some kind of spicy flavor, which has a positive effect on eating and is the main reason why people use spices so often in cooking. The spicy flavor of spices is first and foremost capsaicin, a component that is felt on the tongue and in the mouth, accompanied by a tingling sensation of some sort. The tingling sensation varies from one spice to another and the magnitude of that tingling sensation is closely related to the size of the dosage, the method of use, and the interaction between the intrinsic components of the food.

Traditionally, the taste sensations in China are generally “sour, sweet, bitter, spicy and salty”, and spicy taste is also considered as one of the main taste sensations. However, the modern 4-base taste and 5-base taste do not include spicy taste, but only consider spicy taste as one of the other taste sensations. Japanese flavor scholars do not think that spicy taste is a taste, that spicy taste is a tongue, nose and oral mucosa of the tingling sensation, such as mustard, horseradish spicy taste through the nose irritation, garlic spicy taste of the tongue tingling sensation as well as capsaicin on the oral mucosa of the tingling sensation, etc. belongs to this.

Although the spicy flavor of the human sensory organs with a tingling sensation, but the appropriate use of food flavor can be improved tension, to enhance the appetite is beneficial. Spices are precisely composed of plants with various spicy components that can give people a feeling of excitement when eating. The feeling of spiciness is different, there are “hot” and “spicy”, hot is capsaicin, piperine, etc. on the human sensory stimulation of the effect, while spicy is mustard, horseradish, garlic spicy, the main components of thiocyanate and sulfur ether, etc.. Due to the different ingredients, people perceive spicy flavors differently.

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In addition to cayenne pepper, pepper, mustard and horseradish, there are many other spicy substances such as cinnamon, cloves, musk vanilla, and allspice, etc. The spicy components of these spices are cinnamaldehyde, carvacrol, carvacinone, and eugenol. These components and the direct stimulation of the nasal and oral mucosa pain spicy flavor is different, they are membrane penetration (fat-soluble) as the main way to make the spicy flavor has a certain degree of continuity. Therefore, if you can use the spices with these spicy ingredients in cooking, you can produce excellent results.

Spicy ingredients not only have a strong stimulating effect on the oral mucosa, etc., but also has the physiological effects of accelerating the secretion of adrenaline, promoting metabolic hyperactivity, eliminating mental stress and fatigue.

The product form of spices

A complete spice
Complete spice is the most classic and original method without any processing, such as ginger, garlic peeled and washed directly after use.

Crushed spices
Complete spices after drying and crushed into granules or powder, when used directly added to food, such as pepper, dashi powder.

Third, extracts
Including a variety of solvent extraction of various oleoresins, water-soluble essential oils, water vapor distillates and supercritical carbon dioxide extracted products. Zhu Haitao et al. extracted clove oleoresin from clove with ethanol as solvent, and made a comparison experiment with clove particles and powder from the color, taste, smell and other properties, and the results showed that the comprehensive use of clove oil is higher than particles and powder [3].

Zhu Xiuling et al. used Soxhlet extraction method to optimize the extraction process of purple skin onion oil experiments, in the best process conditions onion oil yield is basically consistent with the theoretical value [4].

Chen Xiong et al. extracted garlic oil using two processes: water vapor distillation and solvent extraction, and analyzed the composition and content of the extracts obtained by different methods, the results show that: the garlic oil obtained by water vapor distillation has a high content of organic sulfides, and the garlic oil obtained by the two methods is obviously different in composition and content [5].

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Fourth, microencapsulated products
Mainly refers to the powdered spice products produced by spray drying method. Zhang Peiyin et al. used gum arabic as a film-forming agent and emulsifier at 70 ℃ for its pretreatment, in which maltodextrin and maltose were added to make microcapsules of anise essential oil with 20% of the essential oil of anise as the core material by spray-drying method. The volatility of anise essential oil was reduced and its antioxidant capacity and its solubility in water were improved [6].

Yan Jianye et al. extracted the volatile oil from anise, and made the volatile oil into an inclusion with β-cyclodextrin to solve the problem of its instability and volatility during storage and use [7].

Wang Yajie used supercritical CO2 extraction method to study the pressure, temperature, time and CO2 flow rate on the ginger oil resin yield, and to determine the optimal process conditions for ginger oil resin extraction [8].

Five, adsorbed in salt, sugar, grains and other dispersible products
Adsorption of essential oils or oleoresin on glucose, table salt, dextrin and other powder carriers, with the effect of instantaneous fragrance, due to the different types of powder carriers, especially β-cyclodextrin, etc. have a certain slow-release effect. However, essential oil and oleoresin will be separated in liquid food. Attention should be paid to the operation: it is easy to deteriorate and volatilize when exposed to air, so it must be kept airtight.

Use of Spice Products

When deciding which spices to use in processed products, it is necessary to take into account not only the aroma of the spice, but also the characteristics of the processed raw materials (e.g., meat, fish, shellfish and vegetables, as well as other auxiliary ingredients) and the process characteristics, etc. The choice is based on the characteristics of the processed material. In modern food processing the direct use of dry powder products is reduced, and if they are used they are more and more often ultra-fine milled products (>30 mesh). This is due to the spices contained in the plant fiber insoluble in water, the use of powdered spices in the rehydration of the product will produce precipitation, which will reduce the grade of the product. Therefore, in the future, a variety of spice extraction and processing products will occupy a larger market.

As the spices contain essential oil components, heating will lead to its loss, so it is very important to choose the best time to add. From the point of view of adding time, it is divided into three stages: pre-treatment of raw materials, processing and cooking (heating) process and out of the pot (heating).

To meat seasoning, for example, often in the meat is heated before sprinkling pepper salt, which belongs to the pre-treatment of raw materials in the processing stage, and then added in the heating, such as cooking soup cooking, etc., this time to add pepper in order to increase the pepper’s aroma and spicy flavor, and play a role in enhancing the appetite. There is also added pepper in the pot, because there are a lot of heat-resistant components in the pepper, add pepper after heating, heating the essential oils in the pepper in the destruction of low, the aroma will be more intense.

References:

[1] Xu Qingping. Spice production technology [M]. Beijing: Chemical Industry Press, 2008.

[2] Song Gang. Introduction to Flavoring Technology [M]. Beijing: Chemical Industry Press, 2009.

［3］ Zhu Haitao, Tang Weidong, Dong Beisen. Preparation and application of clove oleoresin［J］. China Flavorings, 1998(10):15-17.

［4］ Zhu Xiuling, Dai Qingyuan, Che Zhenming, et al. Optimization of Soxhlet extraction process of purple onion oil［J］. Food and fermentation industry, 2010, 36(1):156-160.

［5］Xiong Chen, Xin Qiao, Li Ma. Comparative study of garlic oil extraction［J］. China Flavorings, 1999(5):16-18.

［6］Zhang Peiyin, Zheng Changjiang, Yan Xishang, et al. Research on microencapsulation of essential oils of spices by spray drying method［J］. Food Science, 1998, 19(12):27-29.

［7］ Yan Jianye, Wang Yuanqing, Yu Linhua, et al. Extraction and β-cyclodextrin encapsulation of volatile oil of Anise[J]. Chinese patent medicine, 2010, 32(2):315-317.

［8］ Wang Yajie. Optimization of supercritical CO2 extraction process of ginger oil resin by response surface method [J]. Food Industry, 2013, 34(4):42-44.