Journal of Food Biosciences and Technology
Volume:10 Issue: 1, Winter-Spring 2020

Legumes and pulses have high nutritive values and functional properties that exert positive effects on health and nutrition. This study developed a novel complementary baby food using germinated mung bean and cowpea as sources of extra nutrients supplemented to the infants (aging 6-12 months). The carbohydrate contents of mung bean and cowpea showed 64.3 and 64.0% reduction, respectively, during 48 h of germination. However, phosphorous and zinc contents and antioxidant activities of mung bean and cowpea and the iron content of cowpea increased over the same period of germination. Five baby food formulations were prepared and evaluated according to a standard formula for a commercial baby food which was also used as the control. The finalized formula had higher protein (22.4%), calcium (6,100 mg kg‐1), phosphorus (5,133 mg kg ‐1) and vitamin D (329 IU in 100 g) contents but lower contents of iron (55.5 mg kg ‐1), vitamin C as ascorbic acid (0.1 mg in 100 g) and vitamin B12 (1.2 mg in 100 g) than the control. A finalized formula with good appearance, flavor and taste as well as an overall general acceptance was obtained that can be used to fight mal-nutritional issues in certain developing countries.

Protein hydrolysate is highly regarded as a source of naturally occurring antioxidant peptides. The purpose of this study was to investigate the effect of Ultrasonic (Frequency, 20 KHz; Amplitude, 50%; Time, 30 min) and high-pressure homogenization (Power, 1500 bar; Rated flow, 10 dm/h) pretreatmenton the enzymatic hydrolysis and antioxidant properties of yeast protein hydrolysate obtained from Kluyveromyces marxianus. Trypsin and chymotrypsin were used for protein hydrolysis. Respectively, 73.22%, 23.01% of the total protein was released through sonication and high-pressure homogenization processes. The progress of the enzymatic hydrolysis was evaluated based on the number of free amino groups measured by the O-phetaldialdehyde (OPA) method. 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging activities assays were used to evaluate the antioxidant activity. Sonication pretreatment caused a higher degree of hydrolysis by chymotrypsin compared to high-pressure homogenization. Samples pretreated by high-pressure homogenization exhibited significantly (P<0.05) higher DPPH and ABTS radicals scavenging activity when hydrolyzed by trypsin and higher ABTS radical scavenging activity when hydrolyzed by chymotrypsin. The degree of hydrolysis increased with increasing hydrolysis time.The chymotrypsin was significantly (P<0.05) more effective than trypsin in the hydrolysis of protein. High-pressure homogenization pretreatment and trypsin hydrolysis were considered as the best method for producing yeast protein hydrolysate with DPPH (297.36 µMTE/mg protein) and ABTS (1189.02 µMTE/mg protein) radicals scavenging activities.

Dried carrot pomace (DCP) may be used as a thickening, coloring agent and also a carotenoid-fiber enriched component in food products formulations. The main objective of this study to investigate the effect of DCP from juice industries waste material on the physicochemical, rheological, nutritional properties of ketchup by partial replacement (0.7-3.5%) of tomato paste and the carboxy methyl cellulose. The physicochemical parameters of DCP, including: the moisture, fat, protein, ash, crude fiber, pectin, phenolic compounds content, water holding capacity and color properties were first analyzed. Then, different ketchup samples, based on DCP content variations, were formulated. The physicochemical properties of the formulations as well as the tomato lycopene and DCP β-carotene synergistic effect were studied. Based on the analytical data obtained, the samples with highest viscosity, lowest syneresis and the best color index with (0-2.1%) carrot pomace powder were selected for more detailed investigations to perform carotenoids measurements, color parameters specifications, rheological properties. Finally the formulation with 28% tomato paste, 3% glucose syrup, 0.4% carboxymethyl cellulose and 0.7% DCP was assigned as the best carotenoid-fiber enriched and healthy ketchup product.

Lemon essential oils (LEOs) as a bioactive compound with antioxidative potential are used as safe additives in foods. However, this compound is sensitive to light, oxidation, and processing in order to solve this problem encapsulation could be a suitable technique to protect them from degradation. The aim of this study was to produce nano-encapsulated LEOs in Chitosan: Modified Starch (Hicap) to investigate the antioxidant effect of the addition of 0.5 and 1% (w/w) free and nano-encapsulated LEOs on the quality of fish burgers during storage and compare it to the control. Changes in chemical properties in treated samples at 0, 3, 6, 9, 12, 15 and 18 days of storage were investigated. Our results showed a nanocapsules particle size of about 339.2 nm with high encapsulation efficiency. The addition of nanocapsules prepared by a mixture of CS: Hicap (1.5: 8.5% w/v) in LEOs significantly (P< 0.05) improved the quality characteristics due to the reduction of PV, TBA and TVB-N values for all LEOs nanocapsules treated burgers in comparison to others during storage. Based on the sensory evaluation, the shelf life of burgers increased by incorporation with nano-encapsulated LEOs. According to the results, the application of encapsulated LEOs may be a successful technology for the protection of undesirable chemical, and sensory changes in seafood.

Quality of minced silver carp (Hypophthalmicthysmolitrix) with gum arabic encapsulated with 1 and 1.5%( w/w) and rosemary extract (RE) (1 and 1.5% w/w) stored at 4˚C was studied chemically (peroxide value and total volatile nitrogen) and microbiologically (total viable count, psychrotrophic count) analyses. The efficacy of the encapsulated extract to control the population of Eschershia coli inoculated in silver carp minces was also investigated. Minced silver carp samples treated with gum arabic encapsulated with 1.5% and samples containing rosemary extract significantly showed (P < 0.05) lower peroxide value and total volatile nitrogen content compared to the control during the storage period. Microbial deterioration of the minced samples was restarted by RE as reflected by lower total viable count and psychrotrophic counts in the samples while the lowest counts was observed at 1.5% encapsulated RE. Although encapsulated RE at 1.5% could reduce the population of E.coli on compared to the control and unencapsulated RE treated samples, but it could not control the population of E. coli or reduce it below the acceptable level (<2 log CFU/g). Generally, gum arabic encapsulation could help to obtain higher antimicrobial activity in minced fish.

Formation and structure of whey protein heat-induced gels (100 mg mL-1) through heat treatment at 80 °C and pH modifications at three pH values of acidic (2), isoelectric (5.6) and neutral (7) were studied. The obtained results indicated that the nature of the primary gel networks was different at each pH value. The heat-induced gels produced at pH of 2 and 7, had acceptable overall shape and consistency which confirmed the significant effect of pH on the regular gel structures. Conversely, the amorphous gel structure was observed at isoelectric pH. According to Atomic Force Microscopy images, the structural unfolding of the protein during denaturation and formation of the fibrillar structures was observed in gel at pH of 2 and stranded aggregates at pH of 7. In terms of textural analysis, in samples at pH of 2 and 7, the required force to fracture gel structure was approximately equal and less than that of the sample at pH of 5.6 which goes back to the amorphous large protein aggregates in gel network at isoelectric pH. The ordered, regular and stable gel structures and high ionic balance were reflected in color parameters and lower amounts of moisture content in the gel matrix of samples at pH of 2 and 7 (P<0.05). The well-organized structure and stable gels network along with their desirable functional characteristics, might reinforce their application as food ingredients in terms of improving the qualitative and textural qualities of food products. This property can facilitate the use of these protein gels in novel food systems.

Baked goods are among the most important sources of human food. They may suffer from a limited shelf life due to use of low-quality wheat. However, there are a number of novel dough preparation methods that can improve bread quality. The current study analyzed the effect of the yeast-salt method on the physicochemical and rheological properties of toast dough and bread. Baker’s yeast was used at two levels (0.5 and 1 wt% of flour) along with two levels of salt (1 and 2%) to prepare the yeast-salt solution and the bread dough. Data were analyzed using a completely randomized design and Duncan's multiple range tests. Study results showed that the treatment (1% yeast and 2% salt) had the lowest staleness after 72 hours, dough softening degree and pH, and also the highest water absorption, dough development time, dough stability time, valerimeter value, dough yield, moisture content, ash content, protein content, and sensory profile score compared to other treatments. In general, all yeast-salt method dough preparation treatments had better qualitative properties than the conventional dough preparation method (control). The treatment (1% yeast and 2% salt) was selected as the best study treatment.

Researchers have revealed many novel applications for plum and raisin products as functional natural bakery ingredients. Raisin and plum concentrate were incorporated into the bread formulation at different concentrations and their effects on the rheological, baking properties and shelf life of breads were evaluated. The results showed that the use of plum concentrate at 6% had the highest water absorption, tolerance index, extension time and stability. Firmness of breads decreased by 15% for bread containing 4% raisin concentrate and 40% for bread containing 4% plum concentrate. Minimum firmness was obtained in the sample containing 6% plum concentrate. The addition of raisin and plum concentrates reduced the bread color and brownness of the crust color .The effect of plum concentrate on the color was greater than that of raisin concentrate. Bread containing 4% plum concentrate had the highest volume. By increasing the level of raisin concentration to 4%, the textural properties and general appearance was improved. Although no significant difference was found between the raisin and the plum concentrate in the general acceptance and color, the sensory properties of the sample containing 4% plum concentrate had higher scores by the panel test.

In order to measure the effect of antibacterial nano-covers, the direct contact of covers with meat products mixture was used as a control. Samples were contaminated with standard strains of gram-negative Escherichia coli and gram-positive bacteria Staphylococcus aureus. The samples were compared at specified times (0, 24, 48, and 72 hours). Despite the samples had large number of Staphylococcus aureus, except for one case, the confirmatory tests were found no other positive Staphylococcus aureus coagulase bacteria. This absence, despite the manual infection of two sections out of seven, raised the possibility that the domination of Escherichia coli bacteria prevented the growth of Staphylococcus aureus bacteria in the broth. The hypothesis was tested using a standard method (spot-on-lawn method), and no growth of positive staphylococci coagulase was observed on the Escherichia coli plate. However, the control plates, became turbid due to the growth of bacteria. Lack of growth can be attributed to the use of unsuitable bacteria.

In this research, an industrial spray dryer was used and the effects of atomizer speed on the physicochemical properties of milk powder, the textural and sensory characteristics of white cheese made from this milk powder were evaluated. For this purpose, whole milk was converted into powder by using three different speeds (10,000, 11,000, and 12,000 rpm). The results showed that by increasing atomizer speed in the spray dryer, the average size of casein micelle is significantly decreased (P < 0.05), whereas no significant effect is observed on the chemical properties of milk powder. White cheese characteristics indicated that by increasing atomizer speed, texture parameters, such as hardness, mastication, and gumminess were significantly reduced (P < 0.05). Sensory evaluation also revealed that the cheese samples prepared with dried milk produced at 12,000 rpm were highly accepted by the panelists. Overall, the findings suggested that 12,000 rpm is the optimal atomizer speed for milk powder production.