Plant extract and essential oils added as antimicrobials to cheeses: a review

Abstract

Cheese is a food that is highly susceptible to contamination by pathogenic and spoilage microorganisms, which can result in a decrease in its shelf life and cause serious risks to the consumers’ health. Consumers always require healthy food, free of synthetic preservatives, inducing a search for natural alternatives to ensure safety of the products. Essential oils and plant extracts emerge as an alternative for aiding cheese preservation. Some substances have demonstrated good effects against most pathogens and cheese spoilage microorganisms. However, intrinsic and extrinsic factors may influence the actions of these compounds when incorporated into cheese, besides affecting the product characteristics. This review aims at discussing the antimicrobial efficiency of plant extracts and essential oils as well as the impact of their incorporation on lactic bacteria and the sensory characteristics of products.

Use of thyme essential oil as an antibacterial agent in raw milk intended for the production of farm cheese

“…According to Moro et al (2015), the strong specific flavor of thyme oil, although used in small concentrations, can significantly affect sensory quality of dairy products and may result in their rejection. Gouvea et al (2017) stated that acceptance of food products based on essential oils or plant extracts is extremely important, because having high antimicrobial effect is not enough if consumer doesn't approve it in a sensory way. Divergent results have been reported in several studies, including those of Leuschner and Ielsch (2003), Hayaloglu and Fox (2008), Gammariello et al (2008), who all affirmed that TEO has been successfully incorporated into cheese and have been well accepted by consumers.…”

“…Tayel et al (2015) also confirmed that addition of TEO to cheeses resulted in good sensory acceptance. Gouvea et al (2017) mentioned that general acceptance of cheeses with essential oils and plant extracts can be facilitated if consumers are already familiar with this type of products. To overcome taste problems, Gutierrez et al (2008) proposed combination of different essential oils and extracts to have good antimicrobial effect without affecting product taste and smell.…”

Total nitrogen, water-soluble nitrogen and free amino acids profile during ripening of soft cheese enriched with Nigella sativa seed oil

“…If most hard or semi-hard raw milk cheeses are usually ripened long enough to be safe for consumption, traditional soft cheeses continue to be a real hazard for public safety, as they provide appropriate environment for pathogens survival and development (10,11). A continuous search of antimicrobial solutions, adequate as natural additives in foods in general and in cheeses, in particular, has increasingly been reported by recent studies (12)(13)(14)(15)(16)(17). Enrichment of cheeses with Nigella sativa seed oil (NSSO) has been studied by several authors, mostly for its antimicrobial properties (18)(19)(20)(21)(22).…”

Agar-immobilized basil–lactic acid bacteria bioproducts as goat milk taste-masking agents and natural preservatives for the production of unripened goat cheese

“…Goat milk differs from cow and human milk in having better digestibility, buffer capacity, alkalinity, and therapeutic values, as well as having fat with better physical properties (i.e., surface tension, viscosity, and specific gravity) than cow milk (Park et al, 2007). Goat milk is commonly used for the production of fresh unripened cheese (Janštová et al, 2010), a versatile nutrient-dense dairy product susceptible to physical, chemical, microbiological, and biochemical spoilage that can decrease its shelf life and cause serious risks to consumers' health (Jalilzadeh et al, 2015;Gouvea et al, 2017;Khorshidian et al, 2017). Changes that limit shelf life include creaming of fat, gelation of protein solutions, syneresis of curds and crystallization of minerals, nonenzymatic browning and oxidation of fat, growth of microorganisms, enzymatic degradation, ripening of cheese, and fermentation (Kilcast and Subramaniam, 2011).…”