BACKGROUND Species belonging to the genus Aspergillus have been used in traditional Japanese fermented foods. Aspergillus sojae is a species responsible for strong proteolytic activity. Freeze‐drying treatments followed by physical disruption enables the pulverization of the mycelia of A. sojae RIB 1045 grown in whey protein‐base solid media. Intracellular proteases were extracted using this protocol to compare extracellular protease activity in terms of the reaction’s pH dependence in the presence or absence of inhibitors. RESULT With different sensitivities to inhibitors, intracellular and extracellular proteases showed the strongest activity under acidic conditions, which were considered suitable for cheese application. The raw culture product (CP) and its freeze‐dried product (FDP) were mixed with cheese curds, prepared according to Gouda‐type cheese‐making methods, and were allowed to ripen for 3 months. Chemical analysis of the products showed 13.3% water‐soluble nitrogen (WSN) in the control, which had received noncultured media, whereas 20.0% and 21.1% WSN was found in the CP and FDP experimental cheeses, respectively. Although these adjuncts significantly increased WSN, an insignificant difference was found between CP and FDP. Free fatty acids in all experimental cheeses were similar, showing that CP and FDP caused no rancid defects. CONCLUSION The introduction of freeze‐drying treatments accompanied by cell disruption resulted in a negligible effect in terms of WSN. However, the application of A. sojae can be beneficial when it comes to increasing the level of WSN compared with A. oryzae, as shown in our previous study. © 2020 Society of Chemical Industry

BACKGROUNDThe aims of this study are to (i) evaluate the effects of color enhancers, caramel (C) and molasses (M), on acrylamide and 5‐hydroxylmethylfurfural (HMF) formation in non‐centrifugal cane sugar (NCS) and to (ii) perform nine‐point hedonic scale and evaluation of sensory attributes, encompassing the appearance, flavor, texture and aftertaste, by 71 consumers on NCS, NCS_C, and NCS products made with a blend of molasses and sugar (NCS_MS) and steam processing (NCS_S).RESULTSWith the addition of molasses and caramel at the maximum allowable level of 5 g kg−1 in sugarcane juice, significantly greater acrylamide or HMF did not accumulate in NCS_C and NCS_M during the thermal manufacturing process, while color values of NCS_C significantly changed (P < 0.05). The increases in acrylamide and HMF contents were influenced by pH because they were produced by the Maillard reaction. Hedonic responses showed that NCS_MS was rated with the highest score for overall acceptance, whereas NCS_S, with the lowest content of acrylamide, exhibited the lowest score for every attribute. In addition, the appearance acceptance score of NCS_C was significantly higher than that of NCS (P < 0.05). Significant differences were also found between NCS and NCS_C in the frequency of 9 of 16 items with which consumers selected to characterize the appearance in a check‐all‐that‐apply questionnaire (P < 0.05).CONCLUSIONSThe association between hedonic evaluations and sensory profiles in visual attributes of NCS_C indicated that caramel could be a promising addition in Maillard reaction‐mitigated NCS products to improve consumer preferences through color strengthening without safety concerns. © 2020 Society of Chemical Industry

BACKGROUND Aspergillus sp. has been used in traditional Japanese fermented foods. Protease‐containing culture products of A. oryzae have been applied as the adjunct enzyme source to enrich the flavor in ripened cheese. Although proteolysis was stimulated, the increase of free fatty acids (FFA) was recognized in some products. Since an excess amount of FFA accumulation can cause rancidity in cheese products, the assessment of lipase activity was considered to be essential for the cheese adjunct preparation. RESULTS Although an equal lipase activity from the adjunct materials of A. kawachii NBRC 4308, A. luchuensis RIB 2604 and A. oryzae AHU 7139 was applied to semi‐hard cheese, the FFA level was significantly higher in A. oryzae cheese than in the others. Furthermore, the profiles of volatile components were different in experimental cheeses. An in vitro study with experimental curds demonstrated that the high FFA might not depend on the lipase retainability on curds. On the contrary, the pronounced activation of the lipases occurred in A. oryzae after incubation with the curds. Moreover, incubation of the insoluble lipase that had been attached to the cells with skim milk curd extracts allowed the release of lipases from the cells into the medium with remarkable activation. CONCLUSION A. oryzae AHU 7139 possessed a complex lipolytic system comprising extracellular and cell‐binding lipases that were attributed to the increase in FFA in A. oryzae cheese. © 2022 Society of Chemical Industry.