Investigating the effect of Jashir on the physicochemical properties and sensory and microbial evaluation of probiotic yogurt

Dissertation for Master's Degree in Food Health and Safety

Abstract

Context: Jashir plant grows in cold and mountainous regions of Fars province (Sepidan and .) traditional) use. The indigestible carbohydrates (fiber) found in the leaves of this plant may play a role as prebiotics in probiotic yogurt.

Aim: to investigate the effect of Jashir on the physicochemical properties and sensory and microbial evaluation of probiotic yogurt.

Method: First, 15 kg of 1.5% fat milk, pasteurized and homogenized at 95 degrees Centigrade was heated for 15 minutes, then cooled to 40 degrees Celsius, and 1% w/w of each starter culture (traditional yogurt bacteria (YC-X11) and Lactobacillus casei bacteria (L. Casei 431 DVS) was added to the milk as a starter. Then the samples were kept in a greenhouse at 37 degrees Celsius until pH=4.8 was reached. The yogurts produced until reaching The appropriate consistency and texture were kept in the refrigerator. Then, 10, 20, and 30 grams of prepared yogurt were added to 90, 80, and 70 grams of probiotic yogurt, respectively. The repetition was checked.

Findings: The acidity of the yogurt samples was not significantly different compared to the control yogurt during the storage period. There was a significant difference in the water level of the yogurt samples compared to the control yogurt on days 1, 7, 14, and 21 (p=0.000). The score of sensory characteristics including taste, smell, runny and color of probiotic yogurt samples compared to normal yogurt during the storage period did not have any significant difference except for the oral sensation score. The number of Lactobacillus casei probiotic bacteria (log CFU/ml) in yogurt samples containing Jashir compared to the control yogurt was significantly different on the first (p=0.009), seventh (p=0.040), fourteenth (p=0.000) and twenty-first (p=0.000) days.

Conclusion: In general, it can be concluded that the use of Jashir in Probiotic yogurt was 20%. Jashir kept the acidity in the appropriate range for the survival of probiotics and reduced the amount of water, and due to its nutrients and fiber, it increased the survival time of the probiotic Lactobacillus casei bacteria in the specified range (CFU/ml log106) during the storage period, and this product can be introduced as probiotic yogurt.

Keywords: Jashir, physico-chemical, sensory evaluation and Microbial probiotic yogurt

: Introduction

The genus Pringus1 (Jashir) belongs to the family Amblyphra2 and includes about 30 species (Evans, 1989). 15 species of the genus Pringus (Jashir) are found in Iran, 5 of which are endemic (Mozaffarian, 1996). Some species of Prangus (Jashir) are used in traditional medicine as laxatives, carminatives (Zargari, 1988), invigorating, anti-flatulent, intestinal worm repellants, antifungal and antibacterial agents (Zargari, 1367; Baser et al., 2000; A. Ulubelen, G. Topcu, N. Tan, S. Olcal, S. Tamer, 1995). The compounds of the genus Pringus (Jashir) include a variety of coumarins 3, alkaloids 4, flavonoids 5, terpenoids 6 and gamma pyrone derivatives 7 (Chapman & Hall, London, 1998; Shikishima et al., 2001; Sajjadi, Zeinvand, Shokoohinia, 2009; Razavi et al., 2008).

Jashir It is a member of the genus Pringus belonging to the Chetrian family and with the scientific name of Pringus frulasia8, which is a long and stable plant and is mainly used as a rich fodder for feeding livestock, and it is the most abundant species of Pringus in Iran. On the other hand, Jashir essential oils are secondary plant metabolites that are widely used in the food, pharmaceutical, and health industries as compounds with antimicrobial properties (Amiri, 2016). Also, this plant has been used to treat digestive disorders in traditional Iranian medicine and is known among the general public as a plant with analgesic and anti-inflammatory effects (Imam Qureshi, Taqvi, Javednia, 2013)..  A significant percentage of the essential oil of this plant is composed of hydrocarbon monoterpenes 9 and the only sesquiterpene 10 identified in this essential oil is betacaryophyllene 11 (1.3%). Among the 10 compounds identified in the essential oil, alphapinene 12 (36.6%), betapinene 13 (31.9%) and betaphlandrene 14 (11.7%) are the main compounds (Amiri, 2016).  In terms of nutritional components, it has been determined that the amount of crude protein in the stages of vegetative growth, flowering and seeding was 15.2, 9.4 and 7.2 percent, respectively, and its crude fiber was 15.8, 27.9 and 29.2, respectively. The average high consumption elements of calcium, phosphorus, sodium, and magnesium were measured as 1.7, 0.17, 0.02, and 0.31 percent, respectively, and the average low consumption elements of copper and zinc were measured as 32.8 and 32.6 mg/kg, respectively (Abassi, Maroufi, 1387). 2001). Pringus frolasia Lindel 15 is a plant found in the Mediterranean and Middle East regions, it was noticed as a high energy forage (Martins, Ramos et al. 2013). Aerial parts of Prangus frolasia (Jashir) are usually used as animal food in Iran and some countries (Coskun, Gulsen, Umucallar, 2004). There are reports about the antioxidant and antibacterial activities of Prongus Ferulasia (Coruh, Sagdicoglu Celep, Ozgokce, 2007).

Yogurt 16 from acid fermentation of heated milk by the activity of lactic acid producing bacteria, especially Streptococcus salivarius under the species Thermophilus17 and Lactobacillus delbrueckii under the species Bulgaricus18 in a certain amount, temperature and time It is clearly obtained (Gati Karim, 2008) and it is one of the most widely consumed fermented milk products, which has a positive effect on human health and a special importance in people's diet due to its high nutritional value (Statistics of Agriculture, Livestock and Aquatic Affairs, 2010). Yogurt characteristics such as acidity, free fatty acid content, aroma and flavor compounds (19 diacetyl, 20 acetaldehyde, and 21 acetone) as well as sensory characteristics and nutritional value are important factors in product evaluation. These factors are influenced by factors such as the chemical composition of milk, process conditions, additives, and the activity of initiator bacteria during fermentation. Tammim et al., 1999; Bonzer et al., 2002).

Probiotics 23 are non-pathogenic microorganisms that, if used in sufficient numbers and live, exert beneficial and health-giving effects on their host by creating a microbial balance in the intestine, for this reason they are considered as super-beneficial foods 24.

Lactic acid-producing bacteria, especially Lactobacillus 25 and bifidobacteria 26 are normally a part of the digestive tract ecosystem and are considered probiotics (Homayouni Rad, 2008; FAO/WHO, 2001).

Dairy products seem to be good carriers for delivering probiotics to humans (Champagne and Gardner, 2005), which includes yogurt.

The two main groups of probiotic microorganisms are Lactobacillus (Lactobacillus spp) and Bifidobactrium spp.

The most important species of Lactobacillus are: style="direction: rtl;">L. Acidophilus (L.acidophilus), l. Cellobiose (L. cellobiose), l. Casei (L. casei), L. Corvantus (L. curvatus), L. Delbrueckii subspecies bulgaricus, (L. delbrueckii, SS. bulgaricus), L. Fermentum (L. fermentum), L. Brevis (L. brevis) Reuteri (L. reuteri), L. Rhamnosus (L. rhamnosus) and L. Plantarum. (Lplantarum)

Bifidobacterium longum (Bifidobacterium longum) and Bifidobacterium breve (Bifidobacterium breve) are the most important species of bifidobacterium that are used as probiotics (Kaur, Kuhad, Garg, Chopra, 2008).