Antimicrobial activity of acid-hydrolyzed Citrus unshiu peel extract in milk

Abstract

Citrus fruit (Citrus unshiu) peels were extracted with hot water and then acid-hydrolyzed using hydrochloric acid. Antimicrobial activities of acid-hydrolyzed Citrus unshiu peel extract were evaluated against pathogenic bacteria, including Bacillus cereus, Staphylococcus aureus, and Listeria monocytogenes. Antilisterial effect was also determined by adding extracts at 1, 2, and 4% to whole, low-fat, and skim milk. The cell numbers of B. cereus, Staph. aureus, and L. monocytogenes cultures treated with acid-hydrolyzed extract for 12h at 35°C were reduced from about 8log cfu/mL to <1log cfu/mL. Bacillus cereus was more sensitive to acid-hydrolyzed Citrus unshiu peel extract than were the other bacteria. The addition of 4% acid-hydrolyzed Citrus unshiu extracts to all types of milk inhibited the growth of L. monocytogenes within 1d of storage at 4°C. The results indicated that Citrus unshiu peel extracts, after acid hydrolysis, effectively inhibited the growth of pathogenic bacteria. These findings indicate that acid hydrolysis of Citrus unshiu peel facilitates its use as a natural antimicrobial agent for food products.

Inhibitory effects of Inula britannica extract fermented by Lactobacillus plantarum KCCM 11613P on coagulase activity and growth of Staphylococcus aureus including methicillin‐resistant strains

“…Plant‐derived antimicrobials have been researched and consumed frequently over the past decade to improve quality of health and provide ethnopharmacological remedies (Nittayananta, Limsuwan, Srichana, Sae‐Wong, & Amnuaikit, ; Tang, Prodhan, Biswas, Le, & Sekaran, ). Flavonoid, which is the most abundant type of polyphenolic compound found in plant materials, was studied to increase in concentration and antibacterial activity using acid hydrolysis (Min, Kim, Lee, Kim, & Paik, ), fermentation (Saleh et al, ), and silver nanoparticles (Rashid et al, ). In this study, fermentation was used to increase the antimicrobial activity of I. britannica extract.…”

“…In this study, phenolic compound compo- 2018). Flavonoid, which is the most abundant type of polyphenolic compound found in plant materials, was studied to increase in concentration and antibacterial activity using acid hydrolysis (Min, Kim, Lee, Kim, & Paik, 2014), fermentation (Saleh et al, 2018), and silver nanoparticles (Rashid et al, 2017). In this study, fermentation was used to increase the antimicrobial activity of I. britannica extract.…”

Listeriosis in animals, its public health significance (food-borne zoonosis) and advances in diagnosis and control: a comprehensive review

“…Efforts should also be made for applying control measures at fish ponds since fish products may serve as an important source of listeriosis (Nakari et al 2014). Tannin-rich fraction from pomegranate rind (TFPR) and acid-hydrolyzed Citrus unshiu peel extract have been found to be effective food preservatives in reducing chances of L. monocytogenes contamination in foods Min et al 2014). Food safety control measures must be implemented properly to limit listeriosis and to ensure consistent control strategies (Oyarzabal 2006;Adzitey & Huda 2010).…”

Induction of apoptosis by ethanol extract of <i>Citrus unshiu</i> Markovich peel in human bladder cancer T24 cells through ROS-mediated inactivation of the PI3K/Akt pathway

“…Citrus unshiu Markovich, which belongs to the Rutaceae family, is a citrus fruit that is readily seeded, has no seeds, and is grown in East-Asian countries, including Korea (25,26). For several hundred years, citrus and dried peel have been used as traditional medicines to treat gastrointestinal disorders, colds, indigestion, and bronchial discomfort, and pharmacological activities have been reported for inflammation, allergies, diabetes, and viral infections (27)(28)(29)(30). A study on a tumor-bearing mouse model has shown that C. unshiu peel (Chimpi) extract inhibits tumor growth, which was associated with an increased production of cytokines such as interferon-γ and tumor necrosis factor-α (31).…”