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CN-122004324-A - Processing technology of high-quality black rice tea

CN122004324ACN 122004324 ACN122004324 ACN 122004324ACN-122004324-A

Abstract

The invention discloses a processing technology of high-quality black rice tea, which comprises the following steps of selecting raw materials, selecting mountain black rice, screening, removing impurities, rinsing with weak alkaline clean water, draining, three-stage temperature-control baking and frying, sequentially adopting temperature gradients of 280-290 ℃, 250-260 ℃ and 220-230 ℃ for baking and frying, gradient dewatering, dewatering the baked and fried black rice in an environment of 45+/-2 ℃, cooling, screening, naturally air-cooling, screening by a double-layer vibrating screen, ageing, aroma improving, ageing in a temperature-control humidity-control sealing environment, and sterilizing by microwaves. The invention protects active ingredients on the surface layer of the raw material through weak alkaline rinsing, and three sections of temperature control stir-frying cooperatively generate characteristic aroma and retain nutrition, the step dehydration realizes uniform removal of moisture, simultaneously reduces loss of heat-sensitive ingredients, and aging and microwave sterilization improve aroma coordination and storage stability. The steps are matched cooperatively, so that the obtained black rice tea has rich fragrance and layering, clear tea soup, sufficient nutrition retention, good product uniformity and long shelf life, and is suitable for large-scale deep processing of special black rice.

Inventors

  • Ma Banghan

Assignees

  • 广西宏昇供应链管理有限公司

Dates

Publication Date
20260512
Application Date
20260310

Claims (10)

  1. 1. The processing technology of the high-quality black rice tea is characterized by comprising the following steps of: s1, selecting raw materials, namely selecting the black rice of the mountain as the raw material, and screening to remove broken grains, shrunken grains, impurities and mildew grains to obtain a clean black rice raw material; S2, three-stage temperature control stir-frying, namely placing the clean black rice raw material into stir-frying equipment, and sequentially stir-frying by adopting temperature gradients of 280-290 ℃, 250-260 ℃ and 220-230 ℃ to form 2-acetyl pyrroline aroma components in the process of stir-frying; S3, gradient dehydration, namely placing the roasted black rice in a dehydration environment with the temperature of 45+/-2 ℃ to dehydrate for 10-14 hours, so as to realize high activity retention of anthocyanin; and S4, cooling and screening, namely cooling the dehydrated black rice to room temperature, and screening to obtain a black rice tea finished product with uniform particle size.
  2. 2. The process for processing high-quality black rice tea according to claim 1, wherein the raw material screening in the step S1 further comprises a clear water rinsing process, wherein the screened clean black rice is rinsed 1-2 times with weak alkaline clear water with the pH value of 7.3-7.8, and the black rice is drained until no free moisture exists on the surface of the black rice after rinsing.
  3. 3. The processing technology of the high-quality black rice tea according to claim 1, wherein the total time length of three-stage temperature-control stir-frying in the step S2 is 30-40min, wherein the temperature-control stir-frying is 280-290 ℃ for 5-8min, the temperature-control stir-frying is 250-260 ℃ for 15-20min and the temperature-control stir-frying is 220-230 ℃ for 8-12min, and the stirring speed is 30-40r/min during the stir-frying process.
  4. 4. The processing technology of high-quality black rice tea according to claim 1, wherein the gradient dehydration in the step S3 is stepwise temperature rising dehydration, specifically, the dehydration environment temperature is firstly adjusted to 40 ℃ for dehydration for 4 hours, then the temperature is raised to 45 ℃ for dehydration for 6 hours, and finally the temperature is reduced to 42 ℃ for dehydration for 2 hours.
  5. 5. The processing technology of the high-quality black rice tea according to claim 1, wherein the cooling mode in the step S4 is natural air cooling, the ambient temperature is controlled to be 20-25 ℃ in the cooling process, the relative humidity is less than or equal to 40%, and the cooling is carried out until the center temperature of the black rice tea is consistent with the ambient temperature.
  6. 6. The process for processing high-quality black rice tea according to claim 1, wherein in the step S4, screening is performed by adopting a double-layer vibrating screen, wherein the pore diameter of an upper layer screen is 2.0mm, the pore diameter of a lower layer screen is 1.0mm, agglomerated particles with the particle size of more than 2.0mm and crushed particles with the particle size of less than 1.0mm are removed by screening, and the black rice tea with the particle size of 1.0-2.0mm is collected.
  7. 7. The process for processing high-quality black rice tea according to claim 1, further comprising the step of aging and aroma-improving, wherein the screened black rice tea is placed in a sealed container and aged for 3-5 days in an environment with a relative humidity of 35% -40% at 23-25 ℃.
  8. 8. The process for processing high-quality black rice tea according to claim 7, wherein after the aging and aroma extraction in step S5 are completed, the process further comprises a microwave sterilization process, wherein the aged black rice tea is sterilized by microwaves with the frequency of 2450MHz, the microwave power is 300-400W, and the sterilization time is 60-90S.
  9. 9. The process for processing high-quality black rice tea according to claim 2, wherein the content of selenium in the weak alkaline clear water is 0.010-0.020mg/L, the content of zinc is 0.10-0.14mg/L and the content of strontium is 1.50-1.65mg/L.
  10. 10. A process for processing high quality black rice tea according to claim 3, wherein the thickness of the stir-fried layer of black rice in the stir-frying process is controlled to be 3-5cm.

Description

Processing technology of high-quality black rice tea Technical Field The invention relates to the technical field of food processing, in particular to a processing technology of high-quality black rice tea. Background The black rice is used as a characteristic grain with homology of medicine and food, and has high quality raw materials for deep processing of the grain due to the fact that the black rice is rich in anthocyanin, mineral substances and various amino acids, and has edible value and health care effects, and black rice tea prepared from the black rice is a popular product in the field of natural plant drinks by means of a convenient drinking mode and rich nutrition. The mountain black rice relies on the unique microclimate of the northern return line ecological eugenic zone and the advantages of soil and water sources brought by karst landforms, the anthocyanin content and the iron element content of the mountain black rice are far higher than those of common black rice, and are far more common food materials such as blueberries and spinach, and meanwhile, the irrigation water source of the producing zone is a weakly alkaline deep slit spring which is rich in trace mineral elements such as selenium, zinc and strontium, so that the mountain black rice has higher deep processing value and becomes a preferable raw material for preparing high-quality black rice tea. At present, the conventional processing technology of the black rice tea mostly adopts simple stir-frying and airing dehydration to prepare a finished product, and the technology has a plurality of technical defects although the operation is simple and convenient, the advantages of the raw materials of the characteristic black rice are difficult to fully develop, and the processed black rice tea has uneven quality. In the raw material treatment link, the existing technology only carries out simple impurity screening, does not carry out adaptive rinsing treatment aiming at the raw material characteristics of the black rice, if common water quality rinsing is adopted, nutrients on the surface layer of the black rice are easily damaged, impurities on the surface of the raw material can be remained if rinsing is incomplete, the subsequent baking effect and the cleanliness of finished tea soup are affected, while the temperature control baking is adopted in part of the technology, the baking temperature gradient is single, the baking parameters are not precisely limited, the problem of uneven heating of the black rice is easily caused, characteristic aroma components such as 2-acetyl pyrroline and the like cannot be effectively formed, anthocyanin in the black rice can be decomposed due to high Wen Guodu, and the nutrient retention rate is greatly reduced. In the dehydration link, the existing black rice tea processing mostly adopts a natural sun-drying or constant-temperature dehydration mode, the natural sun-drying is greatly influenced by environmental temperature and humidity, the dehydration efficiency is low, the anthocyanin retention rate is less than 60%, the constant-temperature dehydration is easy to cause uneven moisture removal in the black rice, the problems of turbidity of tea soup and low light transmittance are caused when finished products are brewed, and the drinking experience is influenced. The process handle of the cooling and screening link is also insufficient, the temperature and humidity during cooling are not limited, the black rice is easy to get damp and agglomerate, the screening only adopts a single screen, the uniform grain size of the finished product cannot be ensured, and then the dissolution rate is inconsistent during brewing, and the flavor stability is poor. In addition, the existing black rice tea processing technology generally lacks subsequent aroma optimization and sterilization procedures, the fusion degree of aroma components of the roasted black rice tea is low, a layered aroma structure is difficult to form, and no targeted low-temperature sterilization treatment is performed, so that the total number of finished product bacterial colonies is easily out of standard, and the storage stability and edible safety of the product are affected. In summary, the existing black rice tea processing technology has the problems of unsmooth raw material treatment, no precise regulation and control of baking and dehydration parameters, missing of subsequent quality improvement and sterilization procedures and the like, high activity retention of anthocyanin and other nutritional ingredients in black rice cannot be realized, fragrance level, brewing quality and storage stability of black rice tea cannot be considered, and especially the deep processing requirements of high-nutrition special raw materials such as Mashan black rice cannot be met, so that an optimized black rice tea processing technology is needed, the defects in the prior art are overcome, the raw material advantages of special black rice are fully