Antimicrobial effect of cactus seed extract on the quality and shelf life of French sauce

Dissertation for receiving a master's degree in the field of agricultural engineering, science and food industry, food technology orientation

Abstract

The purpose of this research was to investigate the antimicrobial effect of cactus seed extract as an alternative to chemical preservatives on the chemical, microbial and sensory characteristics of French salad dressing. The tested treatments, French sauce containing chemical preservatives sodium benzoate (0.065% by weight) and potassium sorbate (0.008% by weight) and elderberry kernel extract (0, 0.1, 0.2, 0.3, 0.4, 0.5% by weight), French sauce containing cactus seed extract (0.1, 0.2, 0.3, 0.4, 0.5% by weight) without Chemical preservatives and French sauce did not contain any preservatives (chemical or natural). After production, the product was packed and stored in a refrigerator. All chemical, microbial and sensory tests were performed immediately after production, after 24 hours, one month after production, and two months after production and in three repetitions. The results of statistical analysis showed that the total microbial count in samples containing cactus core extract is significantly lower than the sample without any preservatives (P<0.05). Although the results of the general microbial count test and the mold and yeast count test in some samples containing extract showed a higher amount than the sample containing chemical preservatives, but the final amount was within the permissible range of the national standard. The French sauce containing 0.5% cactus seed extract from the sensory point of view, with a very good score, showed that in terms of flavor and taste, it is more liked by consumers than the French sauce without cactus seed extract. From all of the above, we can conclude that the extract of the cactus core, which until now was considered a part of agricultural waste, can be a natural alternative to the harmful chemical preservatives in the market. Considering that the examination of the composition of the fatty acids of cactus seed extract with gas chromatography indicates the abundance of linolenic acid in this extract, it is possible to use the medicinal benefits of this compound and even introduce a functional product to the country's food industry market.

Key words: French sauce, cactus seed extract, gas chromatography, antimicrobial effect.

Chapter First

1- Research overview

1-1- Preface

With new developments and reforms in the food industry, food safety shows itself to be more important than before. According to published statistics in industrialized countries, more than 93% of people suffer from food poisoning at least once a year. Therefore, there is a need for new methods of controlling microorganisms that cause infection and food poisoning. On the other hand, today in Western societies, the desire for natural foods and reducing the use of synthetic additives in food is more than in the past (Bassole, 2003; Dorman and Deans, 2000). The use of medicinal plants to treat diseases has a history of centuries. Today, although a huge part of the drugs used are chemicals, it is estimated that at least one-third of all pharmaceutical products are of plant origin or have changed form after being extracted from the plant (Ayineh Chi, 1358). 1-2- Statement of the problem. Their constituent compounds can play an effective role in providing the necessary nutrients and energy for humans. Despite the beneficial effects, these products are sensitive to oxidative spoilage due to their high oil content, and during the storage period, their quality characteristics decrease due to microbial and oxidative spoilage. Therefore, the use of compounds with antimicrobial and antioxidant properties can have an effective role in the shelf life of these compounds (Yin & Cheng, 2003). Currently, chemical preservatives are used to achieve this goal.

Today, food factories are looking for alternatives to chemical food additives in order to offer healthier and more natural foods to consumers (Nychas, 1995). Natural spices, extracts and essential oils as antioxidant and antimicrobial compounds, suitable alternatives for chemical antioxidant and antimicrobial substances.. Spices, extracts and natural essences as antioxidant and antimicrobial compounds are suitable alternatives for chemical and synthetic antioxidant and antimicrobial substances. The desire to consume these compounds is due to their naturalness, healthiness, lack of carcinogenic compounds and lack of mutagenic compounds in them (Madsen & Bertelsen, 1995).

Since the 1980s, the desire to produce products with less acidity (decrease vinegar) and less calories (decrease oil) in salad dressings and dressings has increased. Due to the reduction of acetic acid and the increase of the pH of the product, as well as the reduction of the amount of oil and finally, the increase of the aqueous phase and the reduction of the concentration of organic acids and salt, the use of natural additives in all kinds of seasonings and salad dressings has received more attention from a microbiological point of view. In this way, in the new formulation of various food products, especially in seasonings and salad dressings and meat products, the consumption of herbal spices has increased not only as a flavor but also in order to improve the physico-chemical properties and shelf life of various food products (Milani et al., 2018). There is some degree of confusion in the world; But what is clear is that the formulations of sauces in the world are very diverse and their amount is increasing day by day, so that today consumers are faced with a wide range of interesting choices on store shelves. Before 2008, the value of the world sauce market was over 1.3 billion dollars, which grew by 4.8% in 2008 to 2009, and in 2011 it reached It reached 1.4 billion dollars (http://www.preparedfoods.com/articles/109078-salad-dressings-and-sauces).

Because in the sauce process, temperature is not used to make the product healthy, it is necessary to prevent the growth of microorganisms in the sauce storage conditions by using preservative chemical compounds such as benzoic acid and its salts. Due to the fact that the consumption of these compounds (benzoate) in addition to the above-mentioned benefits, they also cause harm to human health. Therefore, it should be tried to use these compounds in the minimum amount (Zhang et al., 2009).

1-4- Research objectives

Therefore, considering the high turnover of all kinds of sauces in the world, which shows the importance and amount of consumption of this food all over the world, as well as the nature of the ingredients and production method of this product, which makes it a suitable substrate for the growth of microorganisms. and also taking into account the value of the cactus plant, the purpose of this research was to investigate the possibility of improving the organoleptic properties of French sauce, including taste, smell, color, texture, in order to increase marketability and create variety, and most importantly, to increase the shelf life of French sauce by adding cactus seed extract to the formulation and reducing the amount of artificial preservatives. More specifically, the objectives of the research are as follows. is:

Production of the optimal formulation of French sauce containing cactus seed extract as a natural antimicrobial compound.

Investigating the effect of adding cactus seed extract on the microbial properties and shelf life of French sauce.

Investigating the antioxidant effect of cactus seed extract in the formulation of French sauce.

Evaluation of the effect of adding cactus seed extract on the sensory characteristics of French sauce.

Comparison of the antimicrobial effect of cactus seed extract with sodium benzoate and potassium sorbate in the formulation of French sauce.

1-5- Research hypotheses

used cactus seed extract as a natural preservative in the formulation of French sauce.

Cactus seed extract does not adversely affect the sensory properties of French sauce.

Cactus seed extract does not adversely affect the physicochemical properties of French sauce.

1-6- Definition of terms and concepts

Sauce: It is a thick liquid sauce that is used as a seasoning to flavor, moisten and enrich salads and dishes. Mayonnaise and salad dressing are the most important types of sauces (National Standard of Iran, 2965).