Pepper decay: take into account the sanitary quality of the washing water

The advise service by Posthavest Technology, UC Davis, by Marita Cantwell and Trevor Suslow, answer regarding a postharvest decay problem in pepper: QuestionAn importer of vegetables recently asked what was causing a decay problem. A severe example is illustrated on the pepper stem shown in the photo.  Other photos showed decay on the fruit surface and a blackish decay on some stem ends.  This issue required expensive repacking of the peppers and considerable losses.  How to minimize this problem.AnswerAt first glance this appears to be bacterial decay. Bacterial decay due to poor sanitation has been a common postharvest issue with peppers.   However it is impossible to definitely diagnose this decay issue without culturing and identifying the organism.  Indeed, from the images provided, there appears to be more than one disorder involved. There are fungal species as well as bacterial species that could result in this sloughing of the stem and slimy decay, but without extensive blackening.  After several back and forth emails with the importer, the following was reported:- The harvest clippers were cleaned frequently and workers sanitized their hands frequently; (however many of the peppers were not cleanly trimmed and had ragged and crushed ends that would be much more susceptible to decay than a clean cut).- The spray wash water had 150 ppm chlorine (a high concentration) and peppers are forced air dried after washing; both pH (6.5-7.0) and chlorine concentration were frequently monitored. - The peppers were handled at 45-50F and the photo above was taken after 13 days. This all seemed a reasonable postharvest handling regime, but had anything changed in the operation?  An important change this season was reuse of the chlorinated water, with two changes daily.  In the past, only single use spray water was used.  The importer insisted that the water quality was checked and could not be contributing to the decay issue.  Since we have limited information on process controls and other water quality parameters and chlorine monitoring was periodic rather than continuous, it does open the possibility that sanitation of the reused water could be the source of the problem.  However, an internal and latent (dormant) fungal infection in combination with harvest damage, water uptake during washing (especially likely at ragged stem cuts), and time at the intermediate storage temperatures, could also result in this type of decay.  Bacterial decay on peppers shows slimy but also darkened stems in the timeframe presented, which was not seen in this case.    Therefore without culturing and identifying the decay-causing organism, the answer to this problem is not obvious. See two previous related Q&A regarding decay on peppers here.Sources of the text and pictureMarch 2016 issue of the Postharvest Technology, UC Davis, newsletter