Functional, Physicochemical, Rheological, Microbiological, and Organoleptic Properties of Synbiotic Ice Cream Produced from Camel Milk Using Black Rice Powder and Lactobacillus acidophilus LA-5

Physicochemical, microbial, and sensory characteristics of yogurt with Persian shallot (Allium hirtifolium Boiss) and probiotic bacteria

The aim of this study was to investigate the characteristics of yogurt prepared with the addition of Persian shallot and probiotic bacteria. The effect of Persian shallot on the viability of probiotic bacteria (Lactobacillus acidophilus and Bifidobacterium bifidum) was evaluated. Furthermore, the antimicrobial effects of shallot and probiotic bacteria on Listeria monocytogenes and Escherichia coli species were investigated. The experiments were performed on days 0, 1, 7, 14, and 21. The results showed that the survival of lactic acid bacteria increased significantly in the presence of shallots (p < .05). The addition of two different probiotic bacteria to the yogurt samples inhibited the pathogenic bacteria. While E. coli bacteria had a 3-log reduction, L. monocytogenes did not grow at all in the presence of probiotic bacteria and shallots. Based on these experiments, it was concluded that the addition of shallots not only increased the survival of probiotic bacteria but also reduced the growth of food-borne pathogenic bacteria. In addition, the addition of probiotic bacteria increased the acceptance of sensory properties of yogurt samples.

The effects of blueberry (Vaccinium corymbosum L.) and jujube fruit (Ziziphus jujube) on physicochemical, functional, and sensorial properties, and probiotic (Lactobacillus acidophilusDSM 20079) viability of probiotic ice cream

The effects of blueberry (BB) and jujube fruit (JF) on the quality parameters, functional, probiotic (Lactobacillus acidophilus DSM 20079) viability, and sensorial properties of probiotic ice cream were investigated. No statistical differences were discovered regarding titratable acidity and L. acidophilus DSM 20079 counts between all samples. However, the ice creams preserved the survivability of probiotic bacteria during the storage period. The probiotic ice creams had counts of viable L. acidophilus DSM 20079 ranging from 8.42 to 8.80 log CFU/g which met the minimum required to achieve probiotic effects after 60 days of storage. Probiotic ice cream with BB or JF had significantly lower L* values than the control, and the BB addition caused the greatest decrease. The addition of both fruits clearly enhanced the total phenolic content and antioxidative activity in ice cream. The incorporation of BB or JF into the ice creams did not statistically affect the overrun value, while the addition of both fruits dramatically affected the first dripping time and increased hardness. Overall, sensory attributes were not significantly altered by the fortification of either fruit relative to the control, so these fruits can be added at higher concentrations to ice cream formulations for further studies.

Characterization and valorization of soybean residue (okara) for the development of synbiotic ice cream

There is an increasing challenge in probiotic viability and stability during food product formulation, processing, and storage. However, synbiotic functional foods have promising potential to deliver the targeted benefits. This study aimed to isolate the okara from soybean residue, and obtained okara flour was further characterized using Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM). Synbiotic ice cream was developed by fortification with Lactobacillus rhamnosus GG and okara at different concentrations (1-3%). Additionally, the synbiotic ice cream was subjected to physicochemical and sensory attributes over 60 days of storage. High viability of L. rhamnosus GG (8.17 log CFU/mL) was observed during storage at 3% okara. Moreover, adding okara at 2% or higher improved viscosity, reduced overrun, and maintained probiotic viability. When compared to the control (ice cream without okara), synbiotic ice cream exhibited a higher protein content and a lower fat level. The synergistic combination of probiotics and okara in ice cream is a potentially novel approach for developing functional ice cream. The addition of okara is not only helpful in increasing the nutritional value of the ice cream but will also be a way forward to minimize agricultural waste. Synbiotic ice cream developed in this study may be considered a potential functional food rich in protein and low in fat.

Some Variation Factors of Freezing Point in Camel Milk

The freezing point degree of milk (FPD) is a classical indicator of cow milk quality. In camel milk, few references are available in the literature regarding the main factors of variation. In the present paper, two methods of FPD determination were used: the Reference method (RM) (using Cryostar) and the Express method (EM), using a milk analyzer (Milkoscan-FT1). The RM was used to determine FPD in 680 bulk raw or pasteurized camel milk samples. Regarding EM, 736 individual milk samples, 1323 bulk samples, 635 samples of pasteurized milk and 812 samples of raw milk used for cheese making were available. The variability of FPD was investigated according to month, lactation stage, milk composition, milk production and microbiological status. Correlations between methods were explored. FPD was highly correlated with most of the milk components and tended to decrease in cases of high contamination by coliforms or high total flora count. However, the weak significant correlations between the two methods indicated the necessity to specifically calibrate an automatic milk analyzer for camel milk.

Dairy Fermentation

Fermented dairy products have been traditionally produced and fermentation has evolved as an effective technique to preserve milk from various milking animals [...]

Preliminary Studies of Bio-Fortification of Yoghurt with Chromium

Yoghurt is a delectable fermented milk product suitable for all ages. Chromium (Cr), a trace mineral is found in two forms: trivalent and hexavalent. Recent studies have shown that the Cr (III), or chromium picolinate (Cri), is beneficial for carbohydrate metabolism. Thus, Cr supplements are used to treat diabetes and manage blood sugar. However, the effect of the incorporation of Cri on starter growth and the quality of yoghurt still needs to be determined. In this study, we aim to produce Cr (CrPi)-fortified yoghurt to fulfil the proposed recommended daily allowance (RDA) of Cr (35–50 µg/day for adults). Additionally, it might act as a nutraceutical for persons with special medical conditions, such as patients with obesity or type 2 diabetes mellitus disease. In this respect, the effect of different concentrations of CrPi, (1, 2, 5, 10, 20 ppm) chromium chloride [Cr (III)] (1, 2, 3, 4, 5 ppm), and potassium chromate [Cr (VI)] (1, 2 ppm) on the activity of yoghurt starter culture were investigated in vitro on de Man, Rogosa, and Sharpe (MRS) media. Compared to the control (without Cr), the obtained data revealed significant inhibition of the yoghurt starter culture by Cr (VI) at 2 ppm compared to Cr (III), which did not affect the bacterial growth up to 5 ppm and was comparable with CrPi [Cr (III)]. We also produced yoghurt supplemented with two doses of Cr (0.25 and 0.5 ppm). We did not observe any significant differences in the physicochemical, rheological, microbiological, and sensory properties of the Cr-fortified yoghurt and the control up to 2 weeks in cold storage. These results clearly indicate that CrPi (0.25 and 0.5 ppm) can be used to manufacture yoghurt with the RDA for intact Cr without affecting its quality.

Antimicrobial Activity of Some Plant Extracts and Their Applications in Homemade Tomato Paste and Pasteurized Cow Milk as Natural Preservatives

Synthetic chemical preservatives are widely used in the food industry to delay the deterioration caused by microbial growth, enzyme activities and oxidation reactions. The last few decades have witnessed marked interest in finding natural food preservatives due to the potential health damage of synthetic preservatives; consumers have become skeptical of consuming foods containing these additives. Polyphenols used as natural preservatives that can be extracted from fruits, vegetables, herbs and spices provide the best alternative for partial or complete replacement of their synthetic analogues. The present study’s emphasis was on employing different plant extracts to be efficiently used as antimicrobial agents for developing replacements for the synthetic chemical additives in food products. The study also investigated the antimicrobial potentialities of five medicinal plants, widely used in Egypt (sumac, tamarind, rosemary, roselle and lemon) against six microbial markers (E. coli, P. aeruginosae, B. subtilis, S. aureus, Penicillium sp. and A. niger.). Sumac extracts showed the best activity against all tested microorganisms, producing the widest inhibition zones ranging from 14 to 45 mm, followed by tamarind and roselle extracts, with inhibition zones ranging from 8–36 and 8–34 mm, respectively. On the other hand, extracts of rosemary and lemon showed variable antimicrobial activity. All extracts from all tested plants were less active against fungal species than bacterial species. In all cases, the organic extracts (80% methanol, 80% ethanol) showed the same or greater activity than the aqueous extracts. In addition, the methanolic extracts showed the strongest and broadest spectrum. The most sensitive strain to plant extracts was B. subtilis, while the most resistant strain was P. aeruginosae. The MIC and MBC or MFC values of methanolic extracts were assayed using the broth dilution method. Sumac extract showed the best activity against all tested microorganisms with the lowest values of MIC and MBC or MFC (from 0.260 to 0.877 and 0.310 to 1.316 mg/mL, respectively, for bacteria, and from 1.975 to 2.5 and 2.5 to 4.444 mg/mL, respectively, for fungi). Interestingly, the tested extracts inhibited microbial growth in tomato paste and pasteurized cow milk for a long storage period (increase shelf life) as compared to the control samples. In conclusion, herbal and spice extracts could be successfully applied as natural antimicrobials for the elimination of food borne microbes and pathogen growth.

Insights into the Microbiological and Physicochemical Properties of Bio-Frozen Yoghurt Made with Probiotic Strains in Combination with Jerusalem Artichoke Tubers Powder

Frozen yoghurt is a refreshing and nutritious dessert, with or without the flavour that combines the texture of ice cream and yoghurt. Several previous studies have been conducted on Jerusalem artichoke tubers due to their components, which contain inulin compounds and other nutrients with beneficial properties of fresh yoghurt. However, limited studies explored the potential benefits of the addition of Jerusalem artichoke tuber powder as a fat replacer on the physicochemical properties and survival of probiotics in frozen yoghurt. In this respect, the aim of this study was to determine the effect of Jerusalem artichoke tuber powder (JATP) (0, 5, 10, 15, and 20% w/w) of the fat source used in the mix as a fat, and sugar replacer in frozen yoghurt production. The microbiological, physicochemical, textural, and sensory properties of frozen yoghurt were investigated. Samples with JATP contained viable counts of bifidobacterium bifidum BGN4 and Lactobacillus casei Lc-01 of 7 log cfu/g during 90 days of storage, as compared to the control sample. The highest viability of probiotics was obtained in the sample formulated with 10% JATP. The formulation of frozen yoghurt with JATP increased the acidity and enhanced the overrun. Compared with the control sample, the incorporation of JATP into frozen yoghurt increased the melting resistance, overrun, and viscosity of the frozen yoghurt. The addition of JATP up to 10% significantly increased sensory attributes. Collectively, the study concluded that the enrichment of frozen yoghurt with JATP up to 20% will provide consumers with health benefits and could be introduced to markets as functional frozen yoghurt.

Effects of Fermented Camel Milk Supplemented with Sidr Fruit (Ziziphus spina-christi L.) Pulp on Hyperglycemia in Streptozotocin-Induced Diabetic Rats

Diabetes is one of the most common chronic metabolic diseases, and its occurrence rate has increased in recent decades. Sidr (Ziziphus spina-christi L.) is a traditional herbaceous medicinal plant. In addition to its good flavor, sidr has antidiabetic, anti-inflammatory, sedative, analgesic, and hypoglycemic activities. Camel milk has a high nutritional and health value, but its salty taste remains the main drawback in relation to its organoleptic properties. The production of flavored or fortified camel milk products to mask the salty taste can be very beneficial. This study aimed to investigate the effects of sidr fruit pulp (SFP) on the functional and nutritional properties of fermented camel milk. SFP was added to camel milk at rates of 5%, 10%, and 15%, followed by the selection of the best-fermented product in terms of functional and nutritional properties (camel milk supplemented with 15% SFP), and an evaluation of its hypoglycemic activity in streptozotocin (STZ)-induced diabetic rats. Thirty-two male adult albino rats (weighing 150–185 g) were divided into four groups: Group 1, nontreated nondiabetic rats (negative control); Group 2, diabetic rats given STZ (60 mg/kg body weight; positive control); Group 3, diabetic rats fed a basal diet with fermented camel milk (10 g/day); and Group 4, diabetic rats fed a basal diet with fermented camel milk supplemented with 15% SFP (10 g/day). The results revealed that supplementation of camel milk with SFP increased its total solids, protein, ash, fiber, viscosity, phenolic content, and antioxidant activity, which was proportional to the supplementation ratio. Fermented camel milk supplemented with 15% SFP had the highest scores for sensory properties compared to other treatments. Fermented camel milk supplemented with 15% SFP showed significantly decreased (p < 0.05) blood glucose, malondialdehyde, low-density lipoprotein-cholesterol, cholesterol, triglycerides, aspartate aminotransferase, alanine aminotransferase, creatinine, and urea, and a significantly increased (p < 0.05) high-density lipoprotein-cholesterol, total protein content, and albumin compared to diabetic rats. The administration of fermented camel milk supplemented with 15% SFP in diabetic rats restored a series of histopathological changes alonsgside an improvement in various enzyme and liver function tests compared to the untreated group, indicating that fermented camel milk supplemented with 15% SFP might play a preventive role in such patients.

Effect of Fermented Camel Milk Containing Pumpkin Seed Milk on the Oxidative Stress Induced by Carbon Tetrachloride in Experimental Rats

Oxidative stress can lead to chronic inflammation, nephrotoxicity, and renal damage. The consumption of plant-based dairy alternatives has increased rapidly worldwide due to their health effects. Bioactive components from natural sources, such as plants, are effective in protecting against oxidative stress. The present study evaluated the physicochemical and sensory properties of fermented camel milk made from camel milk mixed with pumpkin seed milk. Fermented camel milk consists of camel milk mixed with 25% and 50% pumpkin seed milk. This blend (fermented camel milk containing 50% pumpkin seed milk) was evaluated as an antioxidant agent in oxidative stress induced rats. A total of thirty-two male adult albino rats of Sprague Dawley® Rat strain weighing 150–180 g were randomly divided into four groups (n = 8). The first group was solely administered the standard diet and served as the negative control. The other rats (n = 24), received a basal diet, including being intraperitoneally injected with carbon tetrachloride, with a single dose at a rate of 2 mL/kg body weight) as a model for oxidative stress. The oxidative stress rats were divided into three groups; the first group did not receive any treatment and served as the positive control. The second and third groups were administered 10 g/day fermented camel milk and fermented camel milk containing 50% pumpkin seed milk. The results revealed that mixing the camel milk with pumpkin seed milk was more effective in increasing the total solids, protein, ash, fiber, acidity, viscosity, phenolic content, and antioxidant activity. These enhancements were proportional to the mixing ratio. Fermented camel milk containing 50% pumpkin seed milk exhibited the highest scores for sensory properties compared with the other fermented camel milk treatments. The group of rats with oxidative stress treated with fermented camel milk containing 50% pumpkin seed milk showed a significant decrease (p ≤ 0.05) in the levels of malondialdehyde (MDA), low-density lipoprotein (LDL), cholesterol (CL), triglycerides (TGs), AST, ALT, creatinine, and urea, and increased (p ≤ 0.05) high-density lipoprotein (HDL) and total protein and albumin compared with rats with oxidative stress. Consumption of fermented camel milk containing 50% pumpkin seed milk by the oxidative stress rat groups caused significant improvement in all of these factors compared with the positive control group. This study revealed that the administration of fermented camel milk containing 50% pumpkin seed milk to rats with oxidative stress prevented disorders related to oxidative stress compared with the untreated oxidative stress group. Thus, incorporating fermented camel milk might play a beneficial role in patients with oxidative stress.

Impact of Incorporating the Aqueous Extract of Hawthorn (C. oxyanatha) Leaves on Yogurt Properties and Its Therapeutic Effects against Oxidative Stress Induced by Carbon Tetrachloride in Rats

The current study aimed to evaluate the chemical, phytochemical, and sensory properties; the nutritional value; and the antioxidant properties resulting from the incorporation of yogurt fortified with the aqueous extract of Hawthorn leaves in Sprague Dawley rats. The results revealed that the yogurt containing the aqueous extract from Hawthorn leaves exhibited no significant differences in terms of its protein, fat, and ash contents compared to control samples. Moreover, the highest total phenolic content (62.00 ± 1.70) and antioxidant activity (20.60 ± 0.74%) were detected in the yogurt containing 0.4% Hawthorn leaf extract compared to the other samples. The consumption of yogurt fortified with the aqueous extract from Hawthorn leaves by rats experiencing oxidative stress resulted in a significant decrease (p ≤ 0.05) in the triglyceride, total cholesterol, low-density lipoprotein, aspartate aminotransferase, alanine aminotransferase, creatinine, urea, and malondialdehyde levels and a remarkable increase (p ≤ 0.05) in the high-density lipoprotein, total protein, and albumin levels as well as in the total antioxidant potentials of serum compared to the positive control group, indicating that the extract from Hawthorn leaves can play a preventive role against oxidative stress. Collectively, our study concluded that the extract from Hawthorn leaves can provide health benefits to yogurt on the basis of its high bioactive components and can exert protective effects against oxidative stress in rats.