Final answer:
Cakes with higher moisture content maintain freshness longer due to reduced water activity, hindering microbial growth. This principle applies to food preservation where solutes like sugar and salt create high osmotic pressure that detriments microbial survival.
Step-by-step explanation:
Cakes with a higher moisture content tend to retain their moisture and have longer shelf lives. This is because the water activity (aw) of the cake relates to how microbes grow within it, impacting spoilage and shelf life. Microorganisms, which cause food to spoil, need available water to grow. Foods with lower water activity, due to the addition of solutes like salts or sugars, create environments of high osmotic pressure which many microorganisms cannot survive. For instance, honey has high sugar content, making it difficult for microbes to grow, thereby prolonging its shelf life. Similarly, cakes with higher moisture content, when combined with solutes, can have extended shelf lives due to this principle.