Journal of Food and Bioprocess Engineering
Volume:6 Issue: 1, Winter-Spring 2023

In this study, Chia seed mucilage (CSM) as a new source and polyvinly alcohol (PVA) as co-polymer was used to prepare of nanofibers. Different solutions with CSM/PVA volume ratios of 100:0, 80:20, 60:40, 40:60, 20:80, 0:100 were prepared. Results show the increase in the CSM in the polymer solution increased the viscosity, electrical conductivity and viscosity of solution. Scanning electron microscopy (SEM) was to evaluate the morphology of nanofibers. Fourier transform infrared spectrometer (FTIR), X-ray diffraction (XRD), and thermogravimetric analysis (TGA) studies were used to evaluate chemical structure, crystalline structure and thermal characteristics of nanofibers of CSM/PVA. The crystallization index of CSM, PVA, and CSM/PVA nanofibers was 52%, 38%, and 44%, respectively. The non-formation of a new peak and presence of CSM and PVA peaks in the FTIR spectrum of the produced nanofibers are indicative of the lack of chemical reactions between CSM and PVA. Also, the addition of PVA to CSM improves the thermal resistance of the nanofibers.

Pasteurization is regarded as a critical unit operation in the juice processing chain because it extends the juice's shelf life. This study aimed to design, construct and assess the performance of the small-scale low-viscous juice continuous pasteurizer. The pasteurizer is equipped with three shell and tube heat exchangers (STHE) that operate on a counter-current flow system. During operation, raw juice is preheated in the regeneration section before being heated in the heating section to a specified pasteurization temperature. The juice is then held at pasteurization temperature in holding tubes for a specific period before being cooled in the regeneration and cooling section. The performance was evaluated by determining the maximum hot water temperature attainable, product pasteurization temperature and throughput at various pumping speeds of the product. With an initial heating time of 23 minutes, all product pump speeds over 792 rpm can yield a regeneration efficiency of about 50% with a throughput capacity of about 600 L/h. An automated control system can be used to adjust the pasteurizing temperatures. This enables effective use with a wide range of food products with pasteurization temperatures ranging from 72°C to 88°C under High-Temperature-Short-Time (HTST) processing. The logarithmic and quadratic polynomial models were found to be suitable for predicting throughput capacity and pasteurization temperature, respectively. The results from the validation showed R2 values of 97.52% and 99.28% for throughput capacity and pasteurization temperature, respectively. Juice pump speed did not affect the regeneration efficiency (p < 0.05). The pasteurizer is suitable for low-viscous food products.

The present study was performed at two separate stages, the aim of the first stage was to study the effect of two different yeast types (active dry and compressed yeast) using sponge and dough method on various properties of flat bread (pita and Taftoon )prepared by different methods compared to the straight method. The most positive effects on physicochemical and sensory desirability were found in bread samples treated by compressed yeast in the sponge and dough method. After selecting the best sample, adding emulsifiers including SSL and DATEM, and α-amylase as an enzyme at higher level played a key role in increasing the physicochemical and textural values such as moisture, water activity, extensibility, L*, a* and in decreasing the hardness. Furthermore, the general acceptance score of Taftoon bread containing 2 g/kg SSL, 2 g/kg DATEM, and 0.05 g/kg α-amylase was desired more by the panelist, compared with other formulas.

This research study was accomplished for the extension of meat-based hamburgers during frozen storage. Control hamburgers were produced at three ground meat concentrations (30, 70, and 90%). Also, potassium lactate (PL) and sodium diacetate (SD) were added to the hamburger by 3% and 0.15%, respectively, to investigate their effects on moisture content, oxidative stability, and microbial growth. The results showed that the addition of PL and SD relatively maintained the moisture especially when meat ground was 70%. On this basis, after 150 days of storage, moisture was 59.70% for the hamburger with 70% compared with 58.56 obtained for the control. Higher oxidative stability was obtained for the hamburger with PL and SD and meat ground of 30% so that peroxide values were 2.49 and 1.97 meq O2/kg, and 1.82 mg and 1.52 MDA/kg respectively for control and sample after 150 days of storage. The addition of PL and SD inhibited the growth of salmonella, limited the E.coli, molds, and yeasts growth.

Germination is an inexpensive and effective technique that can increase the nutritional quality of flours and change their physicochemical and rheological properties. In this study, three underutilized millet species, namely, Panicum miliaceum, Paspalum scrobiculatum, and Setaria italica were germinated and subsequent changes in their carbohydrate composition, functional characteristics, rheological properties, antinutritional factors and starch granular morphology were analyzed and compared. Germination resulted in significant (p < 0.05) decreases of starch, amylose, amylopectin, and resistant starch contents while increasing the dietary fiber content of the studied millet flours. Water holding capacity and oil holding capacity significantly (p < 0.05) increased; meanwhile the swelling power and water solubility significantly (p < 0.05) decreased in all studied millet flours. Starch granule morphologies were proved by the changes in starch degradation upon germination process. Antinutrients such as phytate and oxalate were significantly lower in germinated millet flours. These findings impress the application of germination in developing nutritionally rich flours with altered functional and rheological properties to incorporate into functional food formulations.

Celiac disease is an autoimmune disorder in which the patient is reacted to the protein gluten. Lifelong adherence to a strict gluten-free diet seems to be an effective treatment. The flour made from gluten-free legumes such as alfalfa (Medicago sativa L.) seeds can be used in bakery products. In this study, alfalfa seed flour (ASF) was incorporated into the formulation of a gluten-free (GF) sponge cake, then the quality, nutritional, and sensory characteristics were evaluated. Rice flour (RF) and corn flour (CF) were replaced in equal proportions with four different ratios of ASF (2.5, 5, 7.5, and 10%). The findings indicated that substituting with ASF led to a significant reduction in the specific volume and porosity of the gluten-free (GF) samples. On the contrary, by increasing the amount of ASF, the hardness of the GF cakes increased (p < 0.05). Replacing the flours with ASF led to a significant increase in moisture, protein, and ash (p < 0.05).  The amount of carbohydrates in the final product was reduced by 22%, and there were no significant changes in the fat content (p > 0.05). The addition of ASF resulted in a significant decrease in the L* value, while the a* and b* values for both the cake's crumb and crust increased (p < 0.05). The iron and calcium contents exhibited a linear increase by ASF substitution (p < 0.05). The Sensory properties were maintained by 2.5 and 5% ASF. To attain the overall quality and sensory properties, the replacement of a small amount of ASF in GF sponge cake is recommended.

Xylooligosaccharides (XOS) are emerging prebiotic that may improve the viability of probiotics and gastrointestinal health. XOS derived from corncob was evaluated for its prebiotic activity with three different probiotic strains. The present study focused on XOS to encapsulate Lactobacillus rhamnosus (LGG) and explore it’s in vitro survival & stability upon storage through structural interactive optimization of encapsulation materials. L. rhamnosus (LGG) showed the highest viability 9.86 ± 0.04 log CFU/mL upon XOS. Among three different carrier types namely, Sodium alginate (SA), Chitosan & Sodium tripolyphosphate (STPP), Whey protein liquid -maltodextrin complex, the SA showed the highest encapsulation efficiency 87.6 ± 0.1%, yield and cost effectiveness. XOS and SA were used for encapsulation of LGG with different formulations. The stability of free and encapsulated LGG was assessed using gastrointestinal conditions. All the treatments provided better encapsulation efficiency > 80 %. M2 formulation showed the highest encapsulation efficiency 92 ± 1%, maximum viability in simulated gastric juice 8.7 ± 0.1 log CFU/mL and bile solution 8.6 ± 0.2 log CFU/mL, resulting significantly (p < 0.05) improved survival when compared with free bacteria. The microcapsules were then incorporated into yoghurt and the results showed that there was an increased survival of probiotics because of the protection of cells by microencapsulation and the promoting effect of XOS on the probiotics growth. The XOS extracted from corncob was successfully incorporated as a prebiotic encapsulation material for effective delivery of L. rhamnosus LGG. The different combinations of wall materials with XOS provided an opportunity to produce beads with better structure and protection.

Noni (Morinda citrifolia L.) has been used for years in traditional medicine. As noni fruit is not utilized by the food industry in Sri Lanka, this study focused on determining the bioactives and functional properties of ripe fruit extract (methanolic and water) and simulated gastrointestinal digesta fractions. Methanol (80%) showed higher extractability of bioactives than water. Moreover, antioxidant and anti-inflammatory properties were higher, and anti-diabetic properties were lower in methanolic extracts than those in water extracts. The total phenolics (TPC) of 198.6 ± 2.48 μmol gallic acid equivalent/g FW, and ascorbic acid, anthocyanin, and β-carotene contents of 53.01 ± 1.47, 57.33 ± 1.01, and 0.27 ± 0.04 μg/g FW, respectively were evident in the fresh fruit. DPPH and ABTS radicals scavenging percentages of the fresh fruit were 97.09 and 98.98, respectively. The total antioxidant capacity of the fresh fruit was 33.94 mg AAE/g FW. Singlet oxygen and Nitric oxide scavenging abilities of the fresh fruit were above 90%. Percentages of heat-induced hemolysis, protein denaturation inhibition, and proteinase inhibitory activities of the fresh fruit at 2 µg/mL were 37.14, 42.32, and 5.23, respectively. Furthermore, alpha-amylase and alpha-glucosidase inhibitory activities of the fresh fruit at 2 µg/mL were 13.7 and 17.0%, respectively. Bioactives and antioxidant, anti-diabetic, and anti-inflammatory activities of dialysable fractions were significantly lower (p < 0.05) than their originals. Positive correlations between TPC and antioxidant activities, and anti-inflammatory and antioxidant activities were evident. This study revealed the therapeutic benefits and appealing sensory attributes that should be developed when producing Noni fruit-incorporated products.

Recently, plant essential oils and their nanoemulsions have received great attention since they help reduce the microbial load and improve the food products’ antioxidant activity. In the present research, rosemary essential oil (REO) and nanoemulations of rosemary essential oil (NREO), were added to a hamburger at different levels, and the properties were checked at refrigerator temperature. The results showed that the most compounds of REO were α-pinene (12.32%), 1, 8-Cineole (12.02%), Camphene (9.21%), Limonene (8.11%), Camphor (7.13%), Bornyl acetate (6.18%), Borneol (6.11%) and Verbenone (5.21%). The mean diameter of inhibition zone against Staphylococcus aureus and E. coli for NREO was considerably more than the one for REO (p ≤ 0.05). The phenol content and antioxidant activity of REO were significantly higher than that of NREO (p ≤ 0.05). In all the studied days, except on the 1st day, the highest amount of peroxide value, thiobarbituric acid and microbial population (mesophilic bacteria, psychrophilic bacteria and coliform bacteria of the samples) belonged to sample 1 (control sample). And the lowest amount of the mentioned factors belonged to hamburger containing NREO (p ≤ 0.05). The highest sensory scores (smell, taste, texture, and overall acceptance) were for hamburger which contained NREO (p ≤ 0.05). The hamburger containing NREO, was selected as the one with the superior treatment due to its lower microbial load, and higher sensory evaluation score.

The determination of ethanol content in non-alcoholic beverages is driven by health concerns and is often imposed by regulating agencies. On the other hand, methanol poisoning leads to high health risks. In addition, the application of the Halal concept in Islamic countries requires the availability of efficient analytical methods. This work reports the development of a simple and sensitive HPLC method for the simultaneous determination of ethanol and methanol in juices and beverages. The method is based on the formation of a stable derivative via the reaction of ethanol and methanol with 9-fluorenylmethyl chloroformate (Fmoc-Cl). The resulting derivatives are detected by a fluorescence detector. The method’s LODs and LOQs were 0.004 g/L and 0.01 g/L, for methanol, and 0.015 g/L and 0.05 g/L, for ethanol, respectively. The mean recovery ranged from 98–109% for both methanol (RSD = 3.7%), and ethanol (RSD = 4.1%). This approach of determination is sensitive and simple in that it requires only a 100 µL sample volume and the reaction product (derivative) can be directly injected without further extraction or pre-concentration. Analysis of a number of non-alcoholic drinks from the domestic market showed that the ethanol content ranged between 0.11 - 0.71 g/L.

In the present study, to prepare the polyphenolic extract of sour grape waste, the simultaneous effect of enzyme (pectinase, Yieldmash) and ultrasound (for 10, 25 and 40 minutes at sound intensity of 30, 60 and 90%) treatments was used and the best sample was encapsulated with maltodextrin and basil seed gum (BSG). To optimize the preparation of microcapsules, Design-Expert 13.0 and response surface methodology (RSM) were used. This design included 3 independent variables of maltodextrin level, BSG level and spray dryer inlet temperature. Finally, the best sample in encapsulation was examined by scanning electron microscope (SEM) and differential scanning calorimetry (DSC). The results showed that by increasing sound intensity, extraction efficiency, total phenol and antioxidant activity increased significantly (p ≤ 0.01). The highest factors were observed in the sample extracted by enzyme and ultrasound at 90% sound intensity for 40 minutes (p ≤ 0.01). In second phase, increasing the inlet temperature of the dryer and the level of maltodextrin as a carrier reduced the encapsulation efficiency and the DPPH radical scavenging activity of the capsules non-linearly. The optimum conditions included 12.129% maltodextrin, 0.5% BSG and the inlet temperature of the dryer of 177.22 °C. The results of DSC showed that the formation of complexes between the compounds led to the formation of heat-stable capsules. The average size of the particles was 1.04 micrometers. According to the results of SEM, the microcapsules had an irregular and quasi-spherical shape. At all the pH and temperatures, the microencapsulated sample had higher stability (p ≤ 0.05). Over time, the bioavailability and release of phenolic compounds increased significantly (p ≤ 0.05).

This study investigated variability in starch properties within a yam-soybean flour blend intended for making Amala. Soybean flour was added at 10-50% levels. Starch was isolated using standard procedures and evaluated for yield, pH, bulk density, swelling power, water and oil absorption, pasting properties, and Fourier Transform Infrared spectroscopy. The result showed that substituting yam flour with soy flour caused significant yield changes in isolated starch from the blends. Higher soybean flour concentration in the composite formulation resulted in decreased starch yield. The pH values also moved towards more acidity with an increase in soybean flour level. The bulk density (0.61 – 0.79 g/cm3), WAC (246.98 – 265.76%), OAC (120.4 – 181.17%) of the isolated starch samples were all found to decrease as a result of soybean flour inclusion. However, the swelling capacity of the isolated starch samples (2.90 – 3.69 g/g) was found to increase with soybean flour inclusion. The pasting properties of the isolated starch samples including peak viscosity (2745 – 5743 cP), breakdown viscosity (318 – 1006 cP), final viscosity (3845 – 8120 cP), and setback viscosity (1178 – 3434 cP) were all found to decrease with the inclusion of soybean flour; while peak time (5.27 – 5.32 min) and peak temperature (82.4 – 85.1 ) increased in values as a result of soybean flour inclusion. The FTIR spectroscopy of the starch samples exhibited differences in the spectra pattern in terms of shifting in the position of the wavenumber and the appearance of new functional groups.