جستجوی مقالات مرتبط با کلیدواژه « خامه قنادی » در نشریات گروه « صنایع غذایی »

One of the most common problems in dairy products, which are rich in unsaturated fatty acids is lipid oxidation. This phenomenon can occur during processing, distribution and storage steps and leads to loss of valuable nutrients, discoloration and unpleasant flavor. Many medical studies confirmed harms and side effects of synthetic additives on human health. Accordingly, extracts and essential oils obtained from medicinal plants have received more attention as natural antioxidants in recent years. The use of phenols in these products has long been supported not only as natural antioxidants but also to produce new tasty and colorful natural products. Therefore, evaluating the function of jujube extract in a dairy emulsion system which is susceptible to oxidation could prove the ability of this fruit to help in processing and enhance the oxidative stability of food products.

At the beginning of this research, ohmic heating system equipped with a temperature regulator was designed and made. This system (a new and green heating technology) was applied in optimal conditions in order to obtain Jujube extract as a rich source of bioactive compounds and in the following, this extract was added to confectionery cream as a natural antioxidant. Confectionery cream samples were produced at the industrial pilot scale according to optimized formulation in the research and development unit of Zarrin Ghazal company. Formulations were contained of jujube extract at the level of 0.5 and 2.5%, synthetic antioxidant butyl hydroxytoluene (BHT) and BHT-extract combination. Assessment of oxidative stability was conducted by measuring peroxide, p-anisidine and total oxidation values during the storage period under different conditions such as darkness and ultraviolet light radiation.

The results showed that cream formulations containing BHT-extract and Jujube extract at the level of 2.5% had the lowest values of total oxidation which represented the highest free radicals inhibitory effect. Evaluation of anisidine number in the absence of ultraviolet light revealed that the growth rate of secondary products oxidation in samples containing jujube extract and BHT separately was significantly lower than the growth rate in control sample. While in the presence of ultraviolet light, only the growth rate of anisidine number of cream containing Jujube extract sample at the level of 0.5% was significantly different in comparison to control sample. However, It was observed that antioxidants in different concentrations and environmental conditions can act as proxidants. The inhibitory mechanism of antioxidants against photo-oxidation was similar to that in samples which were not exposed to light. Therefore, Jujube extract can act as an antioxidant against spontaneous and photo-oxidation. It also demonstrated antioxidant properties in confectionery cream emulsion and BHT-extract combination was affirmed to has synergistic effects against oxidation, due to different functions of polar and non-polar antioxidants. According to the sensory evaluation results, the highest general acceptance score was related to the cream sample containing 0.5% of Jujube extract. The positive effect of this extract on flavor, aroma, texture and desired mouthfeel was determined with a significant difference compared to other samples.

Jujube extract could be used as a natural alternative to synthetic antioxidants in the food and pharmaceutical industries. However, according to the results of sensory evaluation, by increasing the percentage of these compounds a negative impact on overall product acceptance was observed. On the other hand, due to the synergistic effects of polar and non-polar antioxidants and reducing the total oxidation, partial replacement of synthetic antioxidant with natural phenolic compounds is suggested as the optimal option. .Furthermore, fortified cream prepared in the present study could be introduced as a functional food because of health-promoting properties of Jujube extract.

Whipped cream is one of the most popular dairy products with a complex structure of foam emulsion. Production of low fat whipped cream with fat substitutes is recommended with regard to the high fat content in whipped cream and side effects of fat on the public health. Based on, the effects of whey protein concentrate, carboxymethyl cellulose, xanthan gum and mix of them were investigated on the properties of low fat whipped cream. For this purpose, different amounts of them were determined by the surface response design and then they were added to the cream with 20% fat. Then, apparent viscosity, cream firmness, particle size distribution, foam stability, overrun tests, sensory evaluation, color characteristics (L *, a *, b *) were done on the samples. The results showed that fat substitutes in low fat whipped cream compared to the control sample were increased the apparent viscosity, overrun, firmness, foam stability and change in particle size (p<0/05). However, the stabilizers had no alone statistically effects on the color factors. Also, whey protein concentrate in compared with other treatments had the highest overrun and lowest particle size, xanthan gum had the lowest water leakage and carbohydrates, especially xanthan, had the highest viscosity and firmness (p<0/05). Based on the sensory evaluation data, optimal sample that contain 0.35 whey protein concentrate and 0.15 xanthan and carboxymethyl cellulose had statistically more desirable than control and other treatments in texture and overall acceptance. At the end, we pointed out that these additives could be a good alternative to reduce the percentage of fat in whipped cream due to they improve the physical, rheological and sensory properties of whipped cream without significant effects on the most of external parameters such as color and sensory.