ANSI ASABE S521-1991 Method of Determining Peanut Blanchability.pdf

1、 ANSI/ASAE S521 DEC1991 (R2016) Method of Determining Peanut Blanchability American Society of Agricultural and Biological Engineers ASABE is a professional and technical organization, of members worldwide, who are dedicated to advancement of engineering applicable to agricultural, food, and biologi

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6、 and Data approved after July of 2005 are designated as “ASABE“. Standards designated as “ANSI“ are American National Standards as are all ISO adoptions published by ASABE. Adoption as an American National Standard requires verification by ANSI that the requirements for due process, consensus, and o

7、ther criteria for approval have been met by ASABE. Consensus is established when, in the judgment of the ANSI Board of Standards Review, substantial agreement has been reached by directly and materially affected interests. Substantial agreement means much more than a simple majority, but not necessa

8、rily unanimity. Consensus requires that all views and objections be considered, and that a concerted effort be made toward their resolution. CAUTION NOTICE: ASABE and ANSI standards may be revised or withdrawn at any time. Additionally, procedures of ASABE require that action be taken periodically t

9、o reaffirm, revise, or withdraw each standard. Copyright American Society of Agricultural and Biological Engineers. All rights reserved. ASABE, 2950 Niles Road, St. Joseph, Ml 49085-9659, USA, phone 269-429-0300, fax 269-429-3852, hqasabe.org ANSI/ASAE S521 DEC1991 (R2016) Copyright American Society

10、 of Agricultural and Biological Engineers 1 ANSI/ASAE S521 DEC1991 (R2016) Approved February 1993 as an American National Standard Method of Determining Peanut Blanchability Developed by the ASAE Special Crops Processing Committee; approved by the ASAE Food and Process Engineering Institute Standard

11、s Committee; adopted by ASAE December 1991; approved as an American National Standard February 1993; reaffirmed December 1996; reaffirmed by ANSI March 1998; reaffirmed by ASAE December 2001, January 2007; reaffirmed by ANSI January 2007; reaffirmed by ASABE December 2011; reaffirmed by ANSI January

12、 2012; reaffirmed by ASABE and ANSI December 2016. Keywords: Blanchability, Food, Peanut, Test 1 Purpose 1.1 The purpose of this Standard is to: 1.1.1 Establish uniformity and consistency in terms used to describe the blanchability of peanuts. 1.1.2 Define a test procedure that can be used to quanti

13、fy the blanchability of a sample of peanuts for comparison with other samples. 1.1.3 Describe test equipment that ensures accurate control of the test parameters. 2 Terminology 2.1 Blanchability: Ease of skin removal and cleaning of the peanut kernel surface. 2.2 Test: Exposure of peanut sample to c

14、onditions in the blancher for a specified interval of time. 2.3 Preheating: Exposure of peanut sample to a specified temperature for a specified time prior to test. 2.4 Blancher: Laboratory-scale machine for conducting the blanchability test. The blancher includes a blanching chamber, pneumatic syst

15、em, and timing control circuit. 2.5 Whole blanched kernels: Peanut kernels with halves still intact and 100% skin removed. 2.6 Split blanched kernels: Peanut kernels with halves separated and 100% skin removed. 2.7 Partially blanched kernels: Peanut kernels (whole or split) with some portion of skin

16、 removed. 2.8 Unblanched kernels: Peanut kernels (whole or split) with none of the skin removed. 2.9 Blanching time: Time peanut sample is exposed to skin removal action in the blancher, in seconds. 3 Test Equipment 3.1. Blancher. This Standard includes the specifications to construct a blancher whi

17、ch will provide the required test conditions since a commercial model of the blancher is not currently available. A schematic of the blancher is shown in Figure 1. Function and construction detail of the blancher components are described below. ANSI/ASAE S521 DEC1991 (R2016) Copyright American Socie

18、ty of Agricultural and Biological Engineers 2 3.1.1 Blanching chamber. The blanching chamber is an inclined-screen container that rotates inside a clear plastic cylinder mounted to the blancher frame. The screen container mates with a rotating head mounted on a shaft projecting through the base of t

19、he plastic cylinder. Air is injected through a nozzle mounted in the lower side of the plastic cylinder base (see Figure 1). This nozzle introduces a high velocity stream of air which passes through the tumbling peanuts and assists in the removal of skin and kernel particles. Figure 1 Blancher schem

20、atic dimensions in mm (in.) Wright and Mozingo, 1975 3.1.1.1 Plastic cylinder. The plastic cylinder shall be 150 mm (6 in.) in diameter, 460 mm (18 in.) long, and have a removable lid. The lid shall have a 38 mm (1.5 in.) diameter connection in the center for a vacuum line and be grooved to accept t

21、he open top of the screen cylinder. The base of the cylinder shall have seventeen 2.4 mm (3/32 in.) diameter holes equally spaced around the circumference. The vacuum pump pulls extra air (airflow in excess of that introduced with the nozzle) through these holes, through the space between the screen

22、 cylinder and plastic cylinder, and out the opening in the lid. Moisture content of the air flowing through the plastic cylinder is dependent on the laboratory environment. Satisfactory test conditions are achieved in a normal laboratory environment (temperature and relative humidity not greater tha

23、n 25 C (77 F) and 50%, respectively). 3.1.1.2 Screen cylinder. The screen cylinder shall be constructed from 6.4 mm (0.25 in.) mesh screen. It shall be 100 mm (4 in.) in diameter, 445 mm (17.5 in.) long, have an open top, and a screen bottom. The bottom fits snugly into a rotating head slightly larg

24、er in diameter than the screen cylinder. Friction between the screen cylinder and head rotates the screen cylinder. The rotating head is a cylinder 76 mm (3 in.) high, open at the top with a hub and spoke bottom. The hub is 38 mm (1.5 in.) in diameter, and the spokes are 3.2 mm (0.125 in.) diameter

25、metal rods spaced 45 degrees apart. Any hub and spoke arrangement is appropriate as long as the bottom has at least 75% open area. The hub is keyed to the shaft projecting through the base of the plastic cylinder. 3.1.1.3 Drive motor. The drive motor rotates the screen cylinder. Any drive system cap

26、able of maintaining the screen cylinder speed specified in Section 4 Operating Parameters, can be used. 3.1.2 Pneumatic system. The pneumatic system delivers air through a pressure regulator-moisture trap, solenoid valve, and nozzle. Any air supply capable of supplying at least 0.15 m3/min (5.3 ft3/

27、min) at 200 kPa (30 lbf/in.2) gauge for the required period of operation can be used. 3.1.2.1 Pressure regular-moisture trap. The pressure regulator-moisture trap shall be sized for a rated flow of 1.5 m3/min (53 ft3/min) and a maximum pressure of 690 kPa (100 lbf/in.2) gauge. It shall be rated to r

28、emove 100 g of moisture per 1.0 m3/min (35 ft3/min) of flow. 3.1.2.2 Solenoid valve. Any 225 V airline solenoid valve with a 1/4 in.-18 national pipe thread port may be used. ANSI/ASAE S521 DEC1991 (R2016) Copyright American Society of Agricultural and Biological Engineers 3 3.1.2.3 Pressure gauge.

29、The pressure gauge shall be a 0 to 200 kPa (0 to 30 lbf/in.2) gauge with an accuracy of 0.25% full scale. The pressure gauge shall be tee mounted immediately downstream from the solenoid valve at the end of a nominal 1/4 in. dia. 200 mm (8 in.) long pipe nipple. It is beneficial to use some type of

30、snubber at the tee to dampen the pressure surge when the solenoid is actuated. A disk with a 1 mm (0.04 in.) hole mounted in the end of the nipple works well. 3.1.2.4 Nozzle. The nozzle shall be a piece of 4.8 mm (0.1875 in.) outside diameter, OD, copper tubing 127 mm (5 in.) in length attached to t

31、he end of the 9.5 mm (0.375 in.) OD copper supply line. 3.1.3 Control circuit. The control circuit consists of a digital-reset timer, indicator lights, and toggle switches. A wiring schematic for the blancher is shown in Figure 2. Operation is initiated by setting the desired operating time, placing

32、 the power and disable switches in the on position, and pressing the start button (momentary contact). The timer, drive motor, solenoid valve, and vacuum motor start simultaneously and stop when the specified operating time elapses. The disable switch provides a means for stopping operation before t

33、he specified time elapses. The override switches allow operation of either the solenoid valve, drive motor, or vacuum motor independently of the digital timer. Any digital timer with a range of 0.1 to 999.9 s can be used. Figure 2 Wiring diagram for blancher control Wright and Mozingo, 1975. (Wiring

34、 enclosed within dashed lines is integral to commercial digital timer. Timer is used in the momentary start-on delay arrangement.) 3.2 Vacuum system. The vacuum pump shall be capable of developing an airflow of 0.33 m3/min (11.5 ft3/min) through the plastic cylinder (no air injection with the nozzle

35、) and shall have a filter bag to collect the skin and kernel particles. (A canister-type household vacuum cleaner has worked well for a vacuum system.) ANSI/ASAE S521 DEC1991 (R2016) Copyright American Society of Agricultural and Biological Engineers 4 4 Operating Parameters 4.1 The plastic cylinder

36、 should be mounted at an angle of 32 degrees to horizontal. 4.2 The drive motor speed shall be 60 1 r/min. 4.3 Pressure set at the pressure gauge shall be 121 0.5 kPa (17.6 0.1 lbf/in.2) gauge. 5 Test Procedure 5.1 Sample size. The sample of peanut kernels shall be 250 g, Mg. 5.2 Pretreatment. Sampl

37、es shall be preheated in a rotisserie for 9 minutes at 200 C (392 F), allowed to cool to room temperature, and then placed in the blancher. When the blanchability of a series of samples is to be compared, the samples shall be stored in the same environment for 2 days prior to pretreatment and conduc

38、ting the test. The preheat treatment should lower the kernel moisture to a range of 3.75 to 4.0%. 5.3 Blanching time. Blanching time shall be 180 25 s for extra large kernels. For medium size kernels, the blanching time shall be 240 25 s. (Specifications for kernel size classifications are given in

39、USDA Standard, U.S. Standard for Grades of Shelled-Type Peanut.) 5.4 The mass of whole blanched kernels. Mw, split blanched kernels, Ms, partially blanched kernels, Mp, and unblanched kernels, Mu, shall be determined 0.05 g. 5.5 The percentage of blanching loss, PL, shall be calculated. This blanchi

40、ng loss is due to loss of moisture in the preheat treatment and loss of skin and kernel particles in the blanching operation. 6 Test Reporting 6.1 Percentage of whole blanched kernels, Pw, shall be reported. Pw = (Mw / Mg ) 100 (1) 6.2 Percentage of split blanched kernels, Ps, shall be reported. Ps

41、= (Ms / Mg ) 100 (2) 6.3 Percentage of partially blanched kernels, Pp, shall be reported. Pp = (Mp / Mg ) 100 (3) 6.4 Percentage of unblanched kernels, Pu, shall be reported. Pu = (Mu / Mg ) 100 (4) 6.5 Percentage of blanching loss, PL, shall be reported. PL = (Pw + Ps + Pp + Pu) (5) 7 References 7.1 Wright, F. S., and R. W. Mozingo. 1975. Laboratory device for peanut skin removal. Peanut Science 2:11-15. 7.2 USDA, 1981. U.S. Standard for Grades of Shelled-Type Peanut. Source 46FR 63203, Dec. 31, 1981. U.S. Dept. of Agriculture, Fresh Fruit and Vegetable Div., Washington, D.C.