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Commercial Industry Standard of the People's Republic of ChinabzxZ.net
Fresh Lychee
1 Subject Content and Scope of Application
SB/T 10194--1993
This standard specifies the grade specifications, quality indicators, inspection rules, test methods and packaging requirements for the purchase of fresh lychees. This standard applies to the purchase of fresh lychees such as Sanyuehong, Heiye, Nuomici, Guiwei, Huaizhi, Lanzhu, Lingshanxiangli, Yuanhong, Dazao, etc. Other varieties not included can be used for reference. 2 Reference Standards
GB/T601 Preparation of Standard Solution for Titration Analysis (Volumetric Analysis) of Chemical Reagents GB2762 Standard for the Allowable Amount of Mercury in Food
GB2763 Standard for the Residual Amount of 666 and DDT in Foods such as Grains and Vegetables 3 Terminology
3.1 Normal Fruit Shape: The fruit has the inherent shape and characteristics of the variety. 3.2 Moderate Maturity: The fruit reaches the inherent size, color, quality and flavor of the variety. 3.3 Moderate maturity: The fruit has basically reached the inherent size, color, quality and flavor of the variety. 3.4 Normal flavor: The fruit has the inherent flavor of the variety when it matures. 3.5 Empty fruit branches: Fruit branches without fruits on the bunches. 3.6 Gourd nodes (dragon head ya): The enlarged junction between the fruiting mother branch and the fruit branch. 3.7 Uniformity of fruit bunches: The distribution of the same variety of fruit on the bunches. 3.8 Threshing: Fruit without stalks.
3.9 Cracked fruit: Fruit with cracked skin.
) Rot: Fruit corruption and mildew.
3.11 Mechanical injury: Fruit is damaged by pressure or friction. 3.12 Pests and diseases: The peel or flesh is damaged by pests and diseases. 3.13 Foreign pollution: The fruit stalk or fruit surface is polluted by drugs, soot, dust, etc., affecting the appearance. 4 Quality Indicators
4.1 Grades
Lychees are divided into three grades: superior, first-class and qualified. Each grade meets the requirements of the indicators in Table 1. Approved by the Ministry of Domestic Trade of the People's Republic of China on July 24, 1993 292
Implemented on June 1, 1994
Maturity
Uniformity of bunches
Fruit weight
Color and flavor
Mechanical injury,
Diseases and insect pests and
Contamination by foreign objects
Normal fruit shape
Superior product
Fruit is moderately mature
SB/T 10194—1993
Table 1 Grade
First-class product
Normal fruit shape
Fruit is moderately mature
Even distribution of fruit kernels, reading closely
No more than 42 kernels per stem
gram for Sanyuehong, Heiye, Nuomici, Huaizhi, Yuanhong, Dazao and Lanzhu. Guiwei and Lingshan
Xiangli has no more than 48 grains per dry gram,
the grain size is evenly scooped
the fruit is fresh, with the inherent
color of the variety, no discoloration. The flavor is normal
the ear of fruit is no larger than 3 gourd nodes cm,
no empty fruit branches
no rot, cracked fruit, threshing, no
mechanical injury, pests and diseases and foreign pollution
fruits are evenly distributed and tight
Sanyuehong, Heiye, Tangmici, Huai
zhi, Yuanhong, Dazao and Lanzhu
fruit shape is normal
Qualified products
fruit maturity is moderate
fruits are evenly distributed and compact
Sanyuehong, Heiye, Mici, Huai
zhi, Yuanhong, Dazao and Lanzhu
no more than 52 grains per stem, Guiwei and Lingshan
no more than 62 grains per stem, Guiwei and Lingshan
no more than 58 grains per stem,
fruit size is uniform. The number of unqualified fruits is no more than 3% of the total number of grains. The fruit is fresh, has the inherent color of the variety, and has a normal flavor. The number of unqualified fruits is no more than 3% of the total number of grains. The ear of fruit branches is no more than 3cm larger than the gourd node, and there are no empty fruit branches. The number of unqualified fruit branches is no more than 5% of the total number of fruit branches. There is no rot or cracked fruit. Threshing and mechanical threshing are no more than 65 grains per dry gram of Xiangli, and the fruit size is relatively uniform. The number of unqualified fruits is no more than 5% of the total number of grains. The fruit is relatively fresh, has the inherent color of the variety, and has a normal flavor. The number of unqualified fruits shall not exceed 8% of the total number of grains. The ear of fruit branches shall not exceed 3cm of the gourd node, and there shall be no empty fruit branches. The number of unqualified fruit branches shall not exceed 10% of the total number of fruit branches. There shall be no rot or cracked fruit. Threshing, mechanical injury, pests and foreign pollution are not large. The injury, pests and foreign pollution are not large. The number of unqualified fruits shall not exceed 3% of the total number of grains. For other varieties not listed in Table 1, the similar varieties in the table can be referred to according to the characteristics of the varieties. 4.2 Hygiene indicators shall be implemented in accordance with the relevant provisions of GB2762 and GB2763. 5 Inspection rules shall be implemented in accordance with the provisions of this standard when purchasing fresh lychees at the place of production. All lychees of the same variety, grade and purchased at one time shall be regarded as an inspection batch.
5.2 When delivering products, the varieties, grades, and quantitative packaging must be clearly distinguished, and the number and weight of the delivered pieces must be clearly stated. Those that do not meet the requirements should be reorganized by the delivery party and then inspected by the purchasing unit.
5.3 Sampling:
5.3.1 The same batch is taken as the inspection unit, and the sample must be representative. The samples should be taken from different parts of the whole batch of goods, and the inspection results of the samples are only applicable to this batch.
5.3.2 Sampling quantity: 2 pieces are taken for less than 50 pieces, 3 pieces are taken for 51 to 100 pieces, and 1 piece is taken for every additional 100 pieces, with 3 pieces taken for 100 pieces as the base. For scattered and sporadic purchases, random sampling can be carried out from the upper, middle and lower parts of the fruit container, and the number of sampled fruits shall not be less than 3%.
5.3.3 If the quality of litchi is found to be defective during the inspection, it is allowed to take a double amount of samples from the original batch packaging for re-inspection. If the re-inspection still fails, the whole batch of fruits should be downgraded to the corresponding grade.
6 Test method
6.1 Grade specification inspection
6.1.1 Inspection tools:
a. Large platform scale;
b. Small platform scale;
c. Inspection table;
Tape measure or ruler.
SB/T 10194—1993
6.1.2 Inspection procedure: After weighing the sample fruit, spread it on the inspection table, detect the unqualified fruit according to the items specified in the standard, and record the items in kilograms. After each batch of sample fruit is inspected, calculate the inspection results and determine the grade of the batch of litchi. 6.1.3 Operation and evaluation:
6.1.3.1 Fruit shape, color, flavor, uniformity of clusters and degree of maturity shall be identified by sensory organs; fruit weight and length of fruit branches shall be measured by inspection tools. 6.1.3.2 If two or more unqualified items are found on the same fruit, only the item with the greater impact on quality shall be recorded. 6.1.3.3 The percentage of unqualified fruit detected shall be calculated according to formula (1) based on the number of fruits according to the item in the record sheet. If the fruit weight is marked on the package, the percentage shall be calculated according to formula (2) based on the fruit weight, accurate to one decimal place. The calculation method is shown in formula (1) and formula (2).
Unqualified fruit (%) =
Where: X——number of unqualified fruits;
X——total number of fruits.
Unqualified fruit (%)-
W—Total fruit weight, g.
7 Packaging and marking
7.1 Packaging
7.1.1 The container for holding litchi must be solid, firm, clean and beautiful, without peculiar smell, without sharp objects inside and outside, and without insects and mildew. 7.1.2 Carton: Made of corrugated cardboard, the specifications are adopted according to the purchase requirements, and the carton capacity is not more than 10kg. 7.1.3 Bamboo basket is made of green and white winnowing pieces, and the maximum capacity is not more than 20kg. 7.2 Marking
The packaging mark should indicate the variety, grade, net weight, place of origin, packaging date and the code of the packaging personnel. 294
(1)
·(2)
SB/T10194—1993
Appendix A
Fruit morphological characteristics of major litchi varieties
(reference)
Fruit morphological characteristics of major litchi varieties (see Table A1) Table A1Fruit morphological characteristics of major litchi varietiesItem
March red
Heart-shaped or
Crooked heart-shaped| |tt||Oval
Nutrile rice cake flat heart-shaped
Nearly round or
Spherical
Heart-shaped or
Nearly round
Oblong
Nearly round
Or heart-shaped
Spherical
Or round
Oval slightly
Lingshan Fragrant Li
Broad and oblique, especially
Big micro calculation
One side is obvious
obvious bulge
red or blue
round or blunt
round or blunt
cracks
flat, unequal in size
large and flat,
equal in size, arranged relatively
regularly
obvious bulge,
long and narrow,
smooth or slightly bulged longitudinally
irregularly arranged
thick and thin
relatively Small and slightly pointed
convex, arranged neatly
lobed peak
cone-shaped
cone-shaped
suture
not obvious
thick and tough
not obvious
smooth or slightly raised
raised, irregular
or conical
large, of different sizes, raised in arrangement
t||More regular and
There are small
sharp thorns
between
large cracks
The hands are obviously narrow and deep
pointed
sweet with a slight sour taste,
astringent
sweet with a slight fragrance
greasy sweet
sweet with a slight sour taste
sweet with a slight sour taste
sweet with a slight sour taste
sweet with a sour taste
sweet
sweet with sour taste
sweet
with Flowery fragrance
Sweet taste
With fragrance
Mostly large
Mostly small
Various sizes
Mostly small
Mostly small
SB/T10194—1993
Appendix B
Color requirements for main varieties and grades of litchi (reference)
Color requirements for main varieties and grades of litchi (see Table B1) Table B1 Main varieties of litchi Color requirements for key varieties and gradesGrade
Color index
March red
Glutinous rice cake
Lingshan fragrant li
Colored area of superior products
Deep (purple) red
Deep (purple) red
Colored area of inferior products
Deep (purple) red
Deep (purple) red
Appendix C
Reference indexes and inspection methods for the main physical and chemical components of litchi Method (reference)
Main physical and chemical composition indicators (see Table C1)
Edible part
Variety
March red
Nuomici
Lingshan Xiangli
Test method for litchi
Test of edible part
Main physical and chemical components of litchi
Soluble solids
Titratable acid (expressed as malic acid)
g/100 mL juice
Qualified product coloring area
Dark (purple) red
Dark (purple) red
Vitamin C
mg/100ml. Juice
SB/T 10194—1993
C2.1.1 Main instruments and equipment: table balance with a sensitivity of 1g and a load of 1000g, stainless steel knife, beaker (100mL). C2.1.2 Inspection method: Take 1020 sample fruits (representative litchi), weigh the whole fruit, then carefully separate the peel, pulp and seeds, and weigh the weight of the peel plus seeds.
Calculate according to formula (C1):
W. -W× 100
Edible part accounts for the whole fruit (%)=
W. ——Measure the weight of the whole fruit, g; Wi——Measured weight of peel and seeds, g. C2.2 Soluble solids test
·（C )
C2.2.1 Principle of determination: When light passes through solutions of different concentrations, different refractions occur. The higher the soluble solids in the solution, the greater the refractive index. According to the refractive index, the percentage of solids is measured, and the reading error of the determination is ±0.1. C2.2.2 Main instruments and equipment: refractometer or handheld sugar meter, beaker (100mL), medical gauze, hose pipette, stainless steel knife, lens paper.
C2.2.3 Sample solution preparation: Wrap the pulp of 10 fruits with double gauze, place in a mortar and use the mortar rod to squeeze out the juice. The juice is placed in a beaker for testing. This sample solution can be used to determine titratable acid and vitamin C at the same time. C2.2.4 Test method: Before each use, the refractometer or handheld sugar meter must be calibrated to zero with a small amount of distilled water, and then the distilled water must be wiped off with lens paper, and then a small amount of sample liquid is sucked with a rubber head tube and dropped on the refractometer or handheld sugar meter to test the content and calculate the average value of three tests. C2.3 Test of titratable acid
C2.3.1 Determination principle: Based on the solubility of titratable acid in water, the acid-base neutralization method is used, with phenol as the indicator, and the acid content (expressed as malic acid) is calculated from the amount of standard alkali solution consumed in the titration. C2.3.2 Instruments and reagents: analytical balance (sensitivity 0.0001g), oven, volumetric flask (100mL), beaker (1000mL), measuring cylinder (1000mL), weighing bottle (about 20mL), alkali burette (scale 1/20mL), pipette (10mL, 25mL), conical flask (250mL), indicator dropper (50mL), dropper with rubber tip, electric furnace. Phenolphthalein, sodium hydroxide (analytical grade), potassium hydrogen phthalate (analytical grade), ethanol (95%). C2.3.3 Reagent preparation
C2.3.3.1 Phenolic acid: 1% solution (W/V). C2.3.3.2 0.1mol/LNaOH standard solution is prepared according to GB/T601.
C2.3.4 Test method: Take 10mL of juice sample and inject it into a 100mL volumetric flask, add boiled and cooled distilled water to the scale, shake well, take 25mL of this diluted solution and inject it into a 250mL conical flask, add 2 drops of phenol crisp indicator, and add sodium hydroxide standard solution until pink appears. The end point is that it does not disappear within 0.5min.
Titratable acid is calculated according to formula (2):
Titratable acid (g/10 mL juice) = M × × 0.067 × 100V
Concentration of sodium hydroxide standard solution, mol/L; where: M—
V-volume of sodium hydroxide solution consumed in titration, mL; 0.067-mass of equivalent malic acid that reacts with 1.00 mL of 1 mol/L sodium hydroxide, g; V1-amount of juice used for titration, mL (should be 1% 10 according to sample solution preparation
C2.4 Test of vitamin C
X25 -- 2.5 mL).
C2.4.1 Principle of determination: Reduced vitamin C has a strong ability to generate colorless compounds by reducing the dye 2,6-dichlorophenol indophenol. The dye is dark blue in alkaline solution and red in acidic solution. The red color disappears after reduction. Therefore, when the end point is reached, the excess dye appears light red in the acidic medium, and the vitamin C content in the sample is calculated from the amount of dye used. C2.4.2 Instruments and reagents: analytical balance (sensitivity 0.0001g), volumetric flask (50mL), pipette (5mL), conical flask (50ml.), dropper (25mL, 10ml.). Oxalic acid (analytical grade), ascorbic acid (analytical grade), 2,6-dichlorophenol indophenol. C2.4.3 Reagent preparation
C2.4.3.1 Oxalic acid: 2% solution (W/V). C2.4.3.2 Oxalic acid: 1% solution (W/V). C2.4.3.3 Preparation of ascorbic acid standard solution (0.02 mg/mL): weigh 20 mg (accurate to 0.1 mg) of standard ascorbic acid and dissolve it in 1% octadecanoic acid, dilute to 100 ml, take 5 ml of the diluted solution and dilute to 50 ml, ready for use. C2.4.3.4 Preparation of 2,6-dichlorophenol indophenol solution: dissolve 50 mg of 2,6-Dichlorophenol indophenol is dissolved in about 200mL of hot water containing 52mg of sodium bicarbonate, cooled and fixed to 250mL, filtered and stored in a colored bottle in a refrigerator. Before each use, the titer is calibrated with standard ascorbic acid, that is, 5mL of standard ascorbic acid solution is taken into a 50mL conical flask, 5mL of 1% oxalic acid is added and shaken, and 2,6-dichlorophenol indophenol is titrated until the pink color can exist for 15s as the end point, and 5mL of 1% oxalic acid solution is taken for blank test. The titer is calculated according to formula (C3):
Titer T (mg/mL)
Wherein: T—the number of milligrams of ascorbic acid equivalent to each milliliter of 2,6-dichlorophenol indophenol solution; C—the concentration of ascorbic acid, mg/mL;
V—the volume of ascorbic acid absorbed, mL;
V,—the volume of 2,6-dichlorophenol indophenol solution used to titrate ascorbic acid, mLV2—the volume of 2,6-dichlorophenol indophenol solution used to titrate the blank, mL. .....( C3)
C2.4.4 Test method: Sample solution preparation According to the method for determining soluble solids, quickly pipette 5mL of sample solution into a volumetric flask, immediately add 2% oxalic acid to dilute to the mark, shake well, pipette 5mL of solution into a 50mL conical flask, and titrate with a calibrated 2,6-dichlorophenol indophenol solution until the solution turns pink and does not fade for 15 seconds, and perform a blank test at the same time. Vitamin C is calculated according to formula (C4):
(V - Vo):T
Vitamin C (mg/100mL juice)=
Where: V--the volume of dye solution consumed by titrating the sample solution, mL; V. —-the volume of dye solution consumed when titrating the blank, mL; T——2,6-dichlorophenol indophenol dye titer, mg/ml, 5X5=0.5mL).
VThe amount of juice used for titration, mL (50 according to the sample solution preparation method
Parallel determination results, expressed as arithmetic mean, the relative deviation of vitamin C content is not more than 5%. Additional remarks:
This standard is proposed by the Ministry of Domestic Trade of the People's Republic of China. This standard is drafted by the "Lychee Quality" Standard Formulation Group. The drafters of this standard are Zhang Youping, Chen Fang, Ran Dehua, Feng Li, and Yao Chulan. 298
........( C4 )
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