Some standard content:
Light Industry Standard of the People's Republic of China
1 Subject Content and Scope of Application
Bread Yeast
QB1501--1992
This standard specifies the product classification, technical requirements, test methods, inspection rules and marking, packaging, transportation and storage of baker's yeast. This standard applies to bread yeast with fermentation power made from molasses and starchy raw materials by fermentation and ventilation culture of brewer's yeast (Saccharomyces cerevisiae).
2 Reference standards
GB 191
Picture mark for packaging, storage and transportation
Preparation of standard solution for quantitative analysis (volume analysis) of chemical reagents GB601
GB603 Preparation of preparations and products used in test methods of chemical reagents GB2828 Sampling procedures and sampling tables for remote batch inspection General standard for food labeling
GB 77181
3 Terminology
3.1 Fresh yeast: A fermentative cell composed of yeast cells with strong vitality, containing 71%~73% water, commonly known as compressed yeast. 3.2 Active Dry Yeast: Compressed yeast with strong vitality, dry yeast with fermentation power obtained after low-temperature dehydration, with a moisture content of 7.0%~8.5%
3.3 Instant Active Dry Yeast: Compressed yeast with strong vitality, dry yeast with high fermentation power obtained after low-temperature dehydration, with fast fermentation speed and good solubility, with a moisture content of 5.0%6.0%. 3.4 Dough does not contain sugar: refers to the determination of the fermentation power of highly active dry yeast, without adding white sugar to the flour. 3.5 Dough contains 7% sugar: refers to the determination of the fermentation power of highly active dry yeast, with 7% white sugar added to the flour (based on the amount of flour). 4 Product classification
Bread yeast is divided into: fresh yeast, active dry yeast, and highly active dry yeast. 5 Technical requirements
5.1 Fresh yeast
5.1.1 Sensory requirements are shown in Table 1.
Light yellow
It has a special cyanide smell of alcohol, no odor, no softness, no stickiness
No foreign matter
Approved by the Ministry of Light Industry of the People's Republic of China on June 8, 1992 138
Light yellow to light yellow brown
Implemented on February 1, 1993
Physical and chemical requirements are shown in Table 2.
Fermentation power.mL(CO.)
Acidity.mL
Water, %
Active dry yeast and highly active dry yeast
5.2.1 Sensory requirements are shown in Table 3.
QB 1501—1992
Commercial active dry yeast
Light yellow to light yellow brown
Grains or strips
Has a special smell of yeast, no putrefaction, no nasal smell, no foreign matter
Physical and chemical requirements are shown in Table 4.
Fermentation power, mL (CO.)
Water, %
Retention rate, %
6 Test method
Dough does not contain sugar
Dry yeast
Dough contains 7% sugar
The terms and measurement units used in the test method shall comply with the national standards. Secondary
Active dry yeast
The analytical balance, pipette, dropper, volumetric flask and other glassware used shall be calibrated regularly according to the relevant verification procedures. The water used, unless otherwise specified, refers to distilled water or deionized water. The reagents used, unless otherwise specified, refer to analytical grade (AR). 6.1 Fermentation Power
6.1.1 Principle
At 30°C, measure the volume of carbon dioxide produced by yeast fermentation of dough prepared according to specified ingredients within a specified time. This is measured directly using a fermentation instrument, or by using the displacement method to measure the displacement of carbon dioxide. The results are all expressed in milliliters. 6.1.2 InstrumentsbZxz.net
Fermentation power measurement device, see Figure 1
Fermentation instrument,
Constant temperature water bath: control accuracy ±0.5°C;
Balance: sensitivity 0.018:
Dough mixer,
Insulation box.
6.1.3 Reagents and materials
Sodium chloride (GB1266);
Sulfuric acid (GB625);
QB1501-
Discharge: weigh 200g sodium fluoride, dissolve in water, add 20mL sulfuric acid, dilute to 2000mL with water; refined special flour (GB1355);
White sugar (GB 317.1).
6.1.4 Analysis steps
6.1.4.1 Fresh yeast
6.1.4.1.1 Dough preparation
Weigh 280.0g refined special flour and place it in a 30℃ incubator for 1h. Weigh 2.0g fresh yeast sample (if the sample has been refrigerated, place it at 30℃ for 1h in advance) and 2.0g sodium chloride respectively, add 75mL water to the sample and sodium chloride respectively, stir to dissolve, mix evenly and pour into flour, mix with dough mixer for 5min, the dough temperature should be 30℃. 6.1.4.1.2 Determination
a. Method 1
Put the dough into the stainless steel square box of the instrument and send it into the fermentation instrument. The fermentation temperature is 30℃. Adjust the zero point of the recorder and close the venting hole. Start timing from the 8th minute from the dough mixing to the dough being placed in the instrument. Record the amount of carbon dioxide gas produced by the dough in the 1st, 2nd and 3rd hours. The sum of the carbon dioxide gas produced by the dough in the 2nd and 3rd hours is the fermentation power of the yeast. b. Method 2
The determination device is shown in Figure 1. Immediately put the dough into bottle A, and put bottle A into a constant temperature water bath at 30℃±0.5℃, and connect bottle B (bottle B contains 2000mL of drainage liquid). Start timing from the 8th minute from kneading the dough to putting the dough into bottle A. Record the drainage volume of the 1st hour, 2nd hour, and 3rd hour, that is, the amount of carbon dioxide gas produced. All operations should be carried out in a constant temperature room at 30℃. The sum of the drainage volume of the 2nd hour and the 3rd hour is the fermentation power of the yeast. 18cm
A-1000mL wide-mouth glass bottle, B-2500mL small-mouth reagent bottle, C1000 mlL glass volume;
D Constant temperature water bath
Figure 1 Fermentation capacity measurement device
6.1.4.2 Active dry yeast
6.1.4.2.1 Dough preparation
Weigh 280.0g of refined special second flour and place it in a 30℃ incubator for 1h. Weigh 2.8g of active dry yeast and white sugar, add 75mL of water (30℃) to dissolve, and place it in a 30℃ water bath for activation for 30min. Weigh 2.0g of sodium chloride and add 75mL of water to dissolve. After activation, mix the two solutions evenly and pour them into the flour. Mix and stir with a dough mixer for 5min. The dough temperature should be 30℃. 6.1.4.2.2 Determination
a. Method 1
Put the dough into the stainless steel square box of the instrument and send it into the fermentation instrument. The fermentation temperature is 30℃, adjust the zero point of the recorder, and close the small 140
QB15011992
hole for venting. Start timing from the 8th minute from kneading to the time when the dough is put into the instrument. The amount of carbon dioxide gas produced by the dough in the 2nd hour is the fermentation power of the yeast.
The measuring device is shown in Figure 1. Immediately put the dough into bottle A, and put bottle A into a constant temperature water bath of 30℃±0.5℃, and connect bottle B (bottle B contains 2000mL of discharge liquid). Start timing from the & minute from kneading to the time when the dough is put into bottle A. Record the displacement of the 1st and 2nd hours and the amount of carbon dioxide gas produced. All operations should be carried out in a constant temperature room at 30℃. The displacement of the 2nd hour is the fermentation power of the yeast.
6.1.4.3 Highly active dry yeast
6.1.4.3.1 Dough preparation
a. Dough does not contain sugar
Weigh 280.0g of refined special two flour and place it in a 30℃ preservation box for 1h. Weigh 5.0g of highly active dry yeast, add it to the flour, and mix it with a dough mixer for 1min. Weigh 4.0g of sodium chloride, add 160mL of water to dissolve it, pour it into the flour in the dough mixer, mix and stir for 5min, and the dough temperature should be 30℃
: Dough with 7% sugar
Weigh 280.0g of refined special two flour and place it in a 30℃ preservation box for 1h. Weigh 4.0g of highly active dry yeast, add it to the flour, and mix it with a dough mixer for 1m. Weigh 4.0g sodium chloride, 19.6g white sugar, dissolve in 150mL water, pour into the flour in the dough machine, mix and stir for 5min, the dough should be 30℃.
6.1.4.3.2 Determination
Special dough is placed in the stainless steel square box of the instrument and sent to the fermentation instrument. The fermentation temperature is 30℃, the recorder is adjusted to zero, and the venting hole is closed. Start timing from the 8th minute from kneading to the time when the dough is placed in the instrument, and record the amount of carbon dioxide gas produced by the dough in the first hour, which is the fermentation power of the yeast
6.2 Moisture
6.2.1 Principle
The sample is directly dried at 103℃±2℃, and the percentage of mass lost is the moisture. 6.2.2 Instrument
Electric drying oven:
Analytical balance, sensitivity 0.1mg;
c, weighing bottle: 50mm×30mm;
can, drying oven, use color-changing silica gel as desiccant. 6.2.3 Analysis steps
Weigh 3g (accurate to 0.0002g) of crushed fresh yeast sample, or 1g (accurate to 0.0002g) of active dry yeast or highly active dry yeast sample into a weighing bottle that has been dried to constant weight, place it in an electric drying oven at 103℃±2C for 3h, and transfer it to a desiccator for cooling. Weigh it after 30min. Place it in an electric drying oven again, continue drying for 1h, and weigh it until constant weight is reached. 6.2.4 Calculate
mz-m2×100
Where: X.-water content, %
m--mass of weighing bottle, g;
m--mass of bottle plus sample before drying?g;
m2-mass of bottle plus sample after drying, g.
6.2.5 Permissible difference of results
Difference of parallel test determinations: fresh yeast = 0.2%, active and highly active dry yeast ≤ 0.1%. 6.3 Acidity
(1)
1 Standard
6.3.1 Principle
The acidity of the sample shall be determined by acid-base titration. 6.3.2 Apparatus
a. Erlenmeyer flask: 250 mL,
b. Alkaline burette: 10 mL,
c. Balance, sensitivity 0.01 μm.
6.3.3 Reagents and solutions
QB 1501-1992
6.3.3.11% phenolic acid indicator solution, prepared in accordance with GB603. 6.3.3.2 0.1 mol/L sodium hydroxide standard solution, prepared and calibrated according to GB601. 6.3.4 Analysis steps
Weigh 2~3g (weighed to 0.01 g) of fresh alcohol mother sample into a conical flask, add 50 mL of carbon dioxide-free water to dissolve, add 2 drops of 1% phenolic acid indicator solution, and drip 0.1 mol/L sodium hydroxide standard solution until it turns slightly red. The end point is that it does not fade for 15 seconds, and the number of rises and falls of the sodium hydroxide standard solution consumed is recorded.
6.3.5 Calculation
Where: X2——acidity, volume of 0.1 mol/L sodium hydroxide standard solution consumed by 100 g sample, mL, C is the concentration of sodium hydroxide standard solution;
V——volume of sodium hydroxide standard solution consumed, mL, m-
mass of sample, g.
6.3.6 Permissible difference of results
For parallel tests, the difference between two titrations should be less than 0.04 mL. 6.4 Preservation rate
6.4.1 Principle
After placing the sample at a certain temperature for a certain period of time, the percentage of the fermentation capacity measured to the fermentation capacity of the original sample is the preservation rate of the sample.
6.4.2 Apparatus
Same as 6.1.2.
6.4.3 Reagents and materials
Same as 6.1.3.
6.4.4 Analysis steps
Put the original packaged active dry yeast or highly active dry yeast in a 47.5℃ incubator, take it out after 7 days of incubation, and determine its fermentation capacity according to 6.1.4.2 and 6.1.4.3.
6.4.5 Calculation
Where: X—preservation rate, %;
A——fermentation capacity of original sample, mL;
A —fermentation capacity of sample after heat preservation, mL. 6.4.6 Permissible difference of results
For parallel tests, the difference between two determinations should be less than 25 mL. 142
(3)
7 Inspection rules
7.1 Grouping
Q#15011992
Products produced with the same raw materials, formula, process, factory name, product name, specification, trademark, packaging line and quality certificate are considered a batch.
7.2 Sampling
Samples shall be drawn according to Table 5.
(Box)
26~150
151~1200
Number of samples
(Box)
Number of sample unit packages
(Bag, block)
Note: () "Sample" refers to the largest box of the product. ② "Unit package" refers to the smallest package unit (bag, block) of large package mail. Qualified judgment number
③If the total weight of the sample unit packages is less than 50g, the sample unit packages should be increased by 50g. 7.3 Delivery inspection
Number of unqualified judgment
7.3.1 Before the product leaves the factory, the quality inspection department of the production factory shall be responsible for batch inspection according to the provisions of this standard. Only products that meet the requirements of the standard and have signed the quality certificate can be produced.
7.3.2 Delivery inspection items include: packaging, net weight, sensory requirements, fermentation power, moisture, acidity. 7.3.3 Delivery inspection judgment rules
7.3.3.1 Take samples according to Table 5 and check the packaging, net weight and sensory requirements. If the number of samples reaches the unqualified number, the whole batch of products will be judged as unqualified.
7.3.3.2 Take the number of unit packages according to Table 5 and divide the sample into two parts. One part will be sealed for 3 months (fresh yeast shall not exceed 7 months) for future reference, and the other part will be used for physical and chemical analysis. If one of the indicators does not meet the requirements of this standard, samples can be taken from the double amount of packaging for re-testing, and the re-testing results shall prevail. If any of the indicators fails, the whole batch of products will be judged as unqualified. 7.4 Type inspection
7.4.1 Under normal circumstances, enterprises conduct type inspection once a quarter, but if any of the following situations occurs, type inspection shall also be carried out. I
Change the main raw materials and ingredients:
Change the key process#
The national quality supervision agency proposes a requirement for type inspection. 7.4.2 Type inspection items: In addition to the delivery inspection items, it also includes the preservation rate. 7.4.3 Type inspection judgment rules
Perform according to 7.3.3.
7.5 When the supply and demand parties have a dispute over product quality, the two parties can negotiate and select an arbitration unit to analyze and judge according to this standard. 8 Marking, packaging, transportation, storage
8.1 Marking
8.1.1 The label of the sales package must comply with the relevant provisions of GB7718. The label of the inner package should indicate: product name, manufacturer name, factory address, trademark, production date (batch number), net weight, shelf life, and implementation of a
standard code.
, The outer packaging box should indicate: product name, manufacturer name, factory address, trademark, production date (batch number), net weight, gross weight, and words such as "moisture-proof" and "handle with care".
Note: The product name must be consistent with the classification,
QB1501-1992
8.1.2 The signs of the storage and transportation diagram must comply with the relevant provisions of GB191. 8.2 Packaging
8.2.1 The packaging materials must comply with the relevant provisions of the "Food Hygiene Law of the People's Republic of China". 8.2.2 Fresh yeast blocks are packaged in different weights of 10 to 500g. The inner packaging uses wax paper, edible plastic film, etc., and the outer packaging uses cartons.
8.2.3 Active dry yeast and highly active dry yeast are packaged in different weights of 5 to 10,000g. The inner packaging uses composite aluminum foil or (non-vacuum, vacuum or inflatable gas). The outer packaging uses cartons. 8.2.4 The allowable tolerance of the net weight of the sales package is shown in Table 6. Table 6
Bread yeast weight
>50~500 g
>500~1000 g
>1000 g
8.3 Transportation
During transportation, it should be protected from rain, snow, sun, high temperature, moisture, heavy pressure and human damage. 8.4 Storage
8.4.1 The fresh yeast block should be placed in the packaging box and should be sent to the cold storage in time and stored at -4~4℃. Allowable tolerance
8.4.2 Active dry yeast and highly active dry yeast should be placed in the packaging box and stored in a cool and dry place below 20℃. 8.4.3 During storage, it should be protected from rats and insects, and should not be stored together with toxic, harmful or smelly substances. 8.5 Shelf life
8.5.1 The shelf life of fresh yeast shall not be less than 7 days; the shelf life of active dry yeast shall not be less than 6 months; the shelf life of highly active dry yeast shall not be less than 12 months.
The enterprise may indicate a shelf life not less than the above provisions based on the product quality. Additional remarks:
This standard is proposed by the Food Industry Department of the Ministry of Light Industry. This standard is under the jurisdiction of the National Food Fermentation Standardization Center. This standard was drafted by the Food Fermentation Industry Science Research Institute of the Ministry of Light Industry and the Shanghai Yeast Factory. The main drafters of this standard are: Wang Bokang, Mo Xiangyun, Kang Yongpu, Xue Yuqin, Wan Ning. 144
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