Chrysosporium species, potential spoilage organisms of chocolate

Abstract

. 1997. Standard methods of analysing foods for the presence of moulds are inadequate for the detection of genera such as Chrysosporium which do not grow at the high water activities of most mycological media. The use of malt, yeast, 50% glucose agar (MY50G) in sealed containers as an enrichment medium allowed time for germination and growth of heat-stressed spores. Three Chrysosporium spp., C. xerophilum Pitt, C. inops (Carmichael) and C. farinicola (Burnside) Skou, were isolated from commercial chocolate bars with a water activity (a w ) of approximately 0·28. Chrysosporium inops was isolated from commercial milk crumb and a new Chrysosporium sp. was isolated from Ghanaian cocoa beans. In chocolates made by coating MY50G agar (a w 0·89) with chocolate (a w 0·27) containing C. inops arthroconidia, two types of deterioration were seen after storage. The first was fat bloom due to recrystallization of the cocoa butter on the outer and inner chocolate surface. The second was growth of C. inops which occurred on the inside chocolate surface adjacent to the MY50G agar filling and on the outside surface after holding at 92% equilibrium relative humidity (erh) for 12 d. There was some evidence that C. inops could grow on the outside of chocolates held at 5·7% erh after 4 months' storage at 25°C. The appearance of the white fungal growth was not unlike fat bloom to the naked eye but was clearly different with the electron microscope.

State‐of‐the‐Art Chocolate Manufacture: A Review

“…The high percentage of soluble solids in cocoa and chocolate results in low a w levels. This means that these foods will only deteriorate when the water absorption allows some xerophilous molds to multiply, for example, Bettsia alvei , Neosartorya glabra , and Chrysosporium xerophilum (Kinderlerer ; ICMSF ; Thompson ; ICMSF ). Some chocolate‐based sweets, however, in particular products containing fillings with an intermediate a w (0.7 to 0.90) are susceptible to deterioration caused by these xerophilic fungi as well as some osmophilic yeasts (Thompson ; De Clercq ), mainly Eurotium spp.…”

Cocoa Agronomy, Quality, Nutritional, and Health Aspects

“…[C. xerophilum Pitt, C. inops (Carmichael), and C. farinicola (Burnside) Skou], being xerophilic fungi, were isolated from commercial chocolate bars with a water activity (a w ) of approximately 0.28 (Kinderlerer, 1997).…”

Fungi and Mycotoxin Occurrence in Cocoa

“…Nevertheless, there are reports of development of xerophilic fungi such as Bettsia alvei , Chrysosporium xerophilum , and Neosartorya glabra in deteriorated chocolate and chocolate confetti [ 14,15 ] . These episodes occur due to inadequate storage problems leading to the formation of an environment with increased availability of water at the interface of the packaging and chocolate when it is stored in environments with high relative humidity.…”