Retrospective look at a 5-year period of almond hulls composition from samples collected by the California Department of Food and Agriculture

This descriptive study with almond hulls (AH) aimed to determine if year and month influenced the probability of a violation occurring for percent crude fiber (as-is basis) and to assess the effect of moisture on violations. In California, the legal definition of AH is based on the percent crude fiber (as-is basis), percent moisture, and percent ash. Almond hulls cannot exceed 15% crude fiber, 13% moisture, and 9% ash. Data for a 5-yr period (2014 to 2018) were obtained from the California Department of Food and Agriculture through a CA Public Records Act request. There were 673 samples of AH that were analyzed for percent crude fiber and percent moisture. There were differences in the probability of violations for years and months. The highest percent crude fiber (as-is basis) occurred in 2014 and the lowest in 2016. Almond hull samples found to be in violation were 4.1 percentage units higher in crude fiber content, 17.4 versus 13.3% crude fiber as-is basis, than those not in violation across all 5 yr. Percent crude fiber (as-is basis) was greater in summer than other seasons. As the percent moisture in the AH increased, the risk of a violation decreased as the percentage of crude fiber on an as-is basis decreased. The proportion of AH samples found to contain greater than 15% crude fiber (as is) over the 5-yr period ranged from 39 to 62% with few samples in violation based on moisture.