The discovery of antibiotics and pesticides has greatly contributed to the social and economic development of human society but, due to the long-term irrational application, it has led to drug-resistant microorganisms, environmental damage, and other hazards, so the selection of alternative natural, safe, and non-hazardous bioactive substances is an effective solution for this problem. D-limonene is a bioactive compound widely present in various plant essential oils, exhibiting excellent broad-spectrum bioactivity and promising prospects for development and clinical application. This review provides a detailed overview of the biological activities of D-limonene, emphasizing its antimicrobial, anthelmintic, insecticidal, and medicinal potential. While nanoencapsulation technology shows promise in improving the physicochemical properties of D-limonene and enhancing its practical applications, it is also crucial to comprehensively evaluate the potential side effects of D-limonene before use.

The Pichia kluyveri, a proliferation commonly found in Sichuan pickles (SCPs), can accelerate the growth and reproduction of spoilage bacteria, causing off-odor development and decay. Although D-limonene, a common natural preservative, effectively restricts P. kluyveri, its inhibitory mechanism remains unclear. This study aimed to elucidate this molecular mechanism by investigating the impact on basic P. kluyveri metabolism. The findings revealed that D-limonene inhibited P. kluyveri growth and disrupted the transcription of the genes responsible for encoding the enzymes involved in cell wall and membrane synthesis, oxidative phosphorylation, glycolysis, and the tricarboxylic acid (TCA) cycle pathway. The results indicated that these events disrupted crucial metabolism such as cell wall and membrane integrity, adenosine triphosphate (ATP) synthesis, and reactive oxygen species (ROS) balance. These insights provided a comprehensive understanding of the inhibitory effect of D-limonene on the growth and reproduction of P. kluyveri while highlighting its potential application in the SCP industry.

To control juice spoilage caused by Alicyclobacillus acidoterrestris (A. acidoterrestris), this study investigated the synergistic antibacterial properties of citral and α-terpineol (S_CT) and its application in apple juice. S_CT at 1× MIC completely inhibited both vegetative cells and spores of within 24 h. It disrupted cell membrane integrity, inducing lipid peroxidation, shrinkage, permeabilization, and depolarization. These changes triggered intracellular redox imbalance, leading to excessive accumulation of reactive oxygen species (ROS) and hydrogen peroxide (H₂O₂), characterized by severe membrane lipid peroxidation, an increased NAD⁺/NADH ratio, and reductions of 84.180% and 70.780% in adenosine triphosphate (ATP) content and catalase activity, respectively, ultimately resulting in A. acidoterrestris cell death. In addition, an S_CT nanoemulsion (S_CTNE) delivery system was developed. Compared with conventional heat treatment, the addition of 1% S_CTNE effectively inhibited the growth of A. acidoterrestris in artificially contaminated fresh apple juice. Under storage at 4 °C and 25 °C, 1% S_CTNE enhanced the volatile flavor profile without significantly altering sensory acceptability or physicochemical properties. Therefore, 1% S_CTNE may serve as a potential complementary strategy for maintaining apple juice quality.