1、机械设计类英文文献及翻译The Sunflower Seed Huller and Oil PressBy Jeff Cox- fromOrganic Gardening， April 1979， Rodale PressIN 2，500 SQUARE FEET， a family of four can grow each year enough sunflower seed to produce three gallons of homemade vegetable oil suitable for salads or cooking and 20 pounds of nutritious
2、, dehulled seed - with enough broken seeds left over to feed a winters worth of birds.The problem， heretofore， with sunflower seeds was the difficulty of dehulling them at home， and the lack of a device for expressing oil from the seeds. About six months ago, we decided to change all that. The job w
3、as to find out who makes a sunflower seed dehuller or to devise one if none were manufactured。 And to either locate a homescale oilseed press or devise one. No mean task.Our researches took us from North Dakota hub of commercial sunflower activity in the nation to a search of the files in the U.S. P
4、atent Office， with stops in between。 We turned up a lot of big machinery， discovered how difficult it is to buy really pure， unrefined vegetable oils， but found no smallscale equipment to dehull sunflowers or press out their oil。The key to success, however， was on our desk the whole time。 In spring
5、1977, August Kormier had submitted a freelance article describing how he used a Corona grain mill to dehull his sunflower seeds, and his vacuum cleaner exhaust hose to blow the hulls off the kernels. A second separation floated off the remaining hulls, leaving a clean product。 Wed tried it， but beca
6、use some kernels were cracked and the process involved drying， we hadnt been satisfied. Now we felt the best approach was to begin again with what we learned from Mr。 Kormier and refine it.Staff Editor Diana Branch and Home Workplace Editor Jim Eldon worked with a number of hand and electricpowered
7、grain mills。 While the Corona did a passable job， they got the best results with the C。S。 Bell 60 hand mill and the Marathon Uni Mill， which is motordriven. ”I couldnt believe my eyes the first time I tried the Marathon, Diana says。 ”I opened the stones to 1/8th inch, and out came a bin full of whol
8、e kernels and hulls split right at the seams. What a thrill that was！”She found that by starting at the widest setting,and gradually narrowing the opening, almost every seed was dehulled。 The stones crack the hulls open, then rub them to encourage the seed away from the fibrous lining。 The Bell hand
9、 mill worked almost as well. ”As long as the stones open at least as wide as the widest unhulled seed， any mill will work,” she says.Because the seed slips through the mill on its flat side, grading is an important step to take before dehulling。 We made three sizing boxes。 The first is 1/4inch hardw
10、are cloth wire screen。 The second is two layers of 1/4-inch cloth， moved slightly apart to narrow the opening in one direction， and the third is two layers of screen adjusted to make a still-smaller opening. Since the smallest unhulled seeds are about the size of the largest hulled kernels, the grad
11、ing step prevents these undersized seeds from passing through unhulled. Processed together at a closer setting, the smallest seeds hulled out。Jim Eldons workshop is littered with strange-looking pieces of apparatus。 They represent initial attempts to build a workable winnowing box， using Kormiers va
12、cuum exhaust idea for a source of air. Jim， Fred Matlack and Diana finally made a box with a Plexiglas front， through which they could observe what was happening.They cut a hole in the back of the box with a sliding cover to regulate the air pressure， and fiddled with various arrangements of baffles
13、。 The result was a stream of hulls exiting through one hole while the kernels fell to the bottom of the box。 Now they were ready to try a five-pound sample of unhulled sunflower seeds to see how much they could recover.The five pounds were graded and dehulled, then winnowed。 We got about one hull fo
14、r every ten kernels in the final, winnowed product. These are easily picked out。 They usually contain kernels still held behind the fibrous strings of the hull. Their weight prevents them from blowing out with the empty hulls。 We found that bugeaten seeds do blow away with the chaff, which was a bon
15、us for cleanliness of the final product. Toss the hulls to the birds， who will find broken seeds among them.Starting with 80 ounces of unhulled seed, we ended up with 41-1/4 ounces of edible whole seeds, 1.8 ounces of damaged seeds suitable for animal feed， and 36.6 ounces of hulls。 It took us about
16、 an hour. Not bad。Sunflower seeds store perfectly in the hulls， but they deteriorate more rapidly when shelled out。 The grain mill dehuller and winnowing box give the gardener a way to have the freshest possible seeds for eating at all times of the year. With the construction of one more piece of eq
17、uipment - the oil press - he can have absolutely fresh， unrefined, polyunsaturated sunflower oil for salads, mayonnaise and cooking.Most light, refined vegetable oils have been extracted using hexane， a form of naphtha. The oil is then heated to boil off the hexane。 Lye is dumped into it. Its washed
18、 with steam， then heated to remove odors and taste before being laced with preservatives and stabilizers. It may feel oily in the mouth， but you might as well taste air. No so with fresh-made sunflower oil - its deliciously yet subtly nutty in flavor， adding unsurpassed flavor to salads.Theres good
19、reason to believe that sunflower oil may become the #1 vegetable oil in the U。S. in a few years。 Its already 1 in health-conscious Europe。 Corn oil has already caught on here for health reasons, and sunflower oil is so much better。 Sunflower oils 70 percent polyunsaturate is just under safflower， wi
20、th corn oil bringing up the rear with 55 percent。 And sunflowers yield 40 percent oil， soybeans only 20 percent。Our oil press is relatively simple， but it must be welded together。 Check the construction directions for details. The press consists of a welded tubular frame which accepts a threeton hyd
21、raulic jack. You may already have one. If not， it can be purchased at most auto and hardware stores for about 16. A metal canister with holes drilled in its sides and one end welded shut holds the mashed sunflower seeds. A piston is inserted in the canister and then inverted and slipped over a pedes
22、tal on the frame. The jack is set in place, and the pressure gradually increased over half an hour. The oil drips from the sides of the canister into a tray the bottom of a plastic jug slipped over the pedestal works fine - which empties the oil into a cup。 You can filter the oil with a coffee filte
23、r to remove pieces of seed and other fine particles that would burn if the oil were used for cooking。 If its for salads or mayonnaise， theres no need to filter it。We first tried using confectionary” sunflower seeds for oil. These are the regular eating kernels were used to seeing. They give less tha
24、n half as much oil as the oilseed types of sunflower. Although you can use confectionary types such as MAMMOTH RUS SIAN for oil， dont expect to get more than an ounce and a half from a pound of seed。 Oilseed produces three or more ounces of oil from a pound of seed and is well worth planting along w
25、ith confectionarytype seeds. Oilseed has another big advantage to prepare it, you can put the whole， unhulled seed into a blender and whiz it until it forms a fine meal, while confectionary seeds must be dehulled first. The entire sequence of grading, dehulling and winnowing is avoided with oilseed.
26、Oil types produce about a tenth of a pound of seed per head in commercial production. Gardeners, with their better soil and care, invariably do better than that。 Our conservative estimate is that 1,280 plants will be enough for three gallons of oil. Spaced one foot apart in rows two feet apart, 1，28
27、0 oilseed plants will take a space 40by56 feet， or 80-by-28 if you want a more rectangular patch to face south。We worked in pound batches， since the canister just holds one pound of mash. After blending, we heated it to 170 degrees F。 (77 deg C） by placing it in a 300-degree F. (149 deg C) oven and
28、stirring it every five minutes for 20 minutes. Heating gets the oil flowing and doubles the yield of oil。 In case youre wondering， coldpressed” oils sold commercially are also heated， and some are subjected to the entire chemical process. The term has no firm meaning within the industry, according t
29、o the literature weve surveyed.Heating does not change the structure of fats. It will not turn polyunsaturated fats into saturated fats. In fact， Dr。 Donald R。 Germann in his book, ”The Anti-Cancer Diet， says that ”。 an unsaturated fat must be heated to high temperatures above 425 degrees F. or 200
30、degrees C。 - at least 8 or 10 times before any shift toward saturation occurs.。 Dean C。 Fletcher， Ph.D。, of the American Medical Association Department of Foods and Nutrition in Chicago, says, Its true that either high temperature or repeated heating does change the nature of some of the unsaturated
31、 oil molecules。 (But) the flavor of the oil changes as these chemical changes occur, spoiling its taste. This effect is probably more profound than any of the physiological changes the altered oil might produce within the body。”From 500 gm. of heated mash， we pressed 89 gm. of oil, 89 percent of the
32、 entire amount available and twice as much as we could press from unheated oil！ The decision is up to you whether or not to heat the mash, but that extra 50 percent seems like an awful lot， especially when the whole technique is so labor intensive。 The oil should be stored in the refrigerator， and i
33、ts probably best to use it within a month, since it has no preservatives. Mayonnaise made with such fresh oils should be kept refrigerated and used within two weeks. The leftover cake， still containing 50 percent of its oil， is a nutritious addition to your dishes， and makes excellent feed for animals or winter bir
