| Author | Message | ||
     Jens Rademacher (Rademacher) |
Hello to All I have a question concerning the storage of samples. I work on developing a calibration for protein and starch in fresh harvested grain. If I have produced a calibration, this should also be checked. Therefore I require fresh material, but that is however then not available. My question now: How could I store the samples, so that they remain as fresh as possible, and no transposition-processes in the material take place? Is there any literature available about this topic? Thanks Jens Rademacher | ||
| hlmark |
Jean - hello! I think we met once, but I don't remember when or where. To respond to your question, while your interest is in keeping the materials fresh for the purpose of NIR measurement, the problem is basically NOT an NIR problem. I would say ou should look into the general agricultural literature to find out what being done for this. Certainly lots of porcesses are available, that are used on all sorts of foodstuffs that are sold in the supermarkets, ranging from irradiation with UV and X-rays to bathing them in ethylene oxide and all sorts of other things. In general, though, for wheat and other grains, NIR results are not too much affected as long as no major changes occur. Probably the hardest to avoid is a change in moisture level. Also, if the grain is to be kept for a long time, then you have to worry about possible biological acitvity changing the samples (rotting, in other, cruder, words). But wheat samples are routinely kept for long time periods. Phil WIlliams should be able to help out there. Howard | ||
| David Hopkins (Hopkins) |
Jens, I agree with Howard's comments. I have experience with storage of grain for NIR sample library. At DICKEY-john, we used 4-mil zip-lock polyethylene bags for the samples, to maintain the moisture fairly well, and storage at 5-7 C. We could store the lower moisture samples indefinitely, but sometimes the higher moisture samples went bad (rotted or got mouldy) after several years. Some people add other chemicals, such as mothballs, but we did not find that necessary, and we were concerned that some chemicals might combine with components in the grain and possibly change the spectra of the grain. Hope this helps. Regards, Dave Hopkins | ||
| Ian A. Cowe |
Jens, Storage of grain for NIR is a similar problem to grain storage generally. If the moisture content coming off the field is less than 12% then you can usually store it at room temperature in storage jars or sealed metal foil packets. One problem to consider is infestation. Insects in grain can very quickly lead to grain spoilage. It isimportant to have insect traps in your grain store and also High Tension UV insect killergrids. Your storage jars should have seals to prevent insects migrating up the screw threads of the jars. If the mosuiture is greater than 12% then storage at 4C in metal foil packets which are heat sealed is the only alternative. As David says this is not guarenteed to be a permanent solution but I have kept samples for over a year at moistures near 20%. Hope this helps Regards Ian A. Cowe | ||
| Art Springsteen |
Having seen Ian and David's posting, I think this is pretty well handled but I wonder why no one has mentioned sealing the samples using one of these inexpensive commercial vacuum sealers that are used on food? Since the vacuum is so slight, I don't think you're changing the water content very much. Give the bags a zap with UV to kill the bugs or irradiate them and it should handle the problem. Or am I way off base? Art S. |