Sai Kranthi Vanga

Review of Conventional and Novel Food Processing Methods on Food Allergens

ABSTRACT With the turn of this century, novel food processing techniques have become commercially very important because of their profound advantages over the traditional methods. These novel processing methods tend to preserve the characteristic properties of food including their organoleptic and nutritional qualities better when compared with the conventional food processing methods. During the same period of time, there is a clear rise in the populations suffering from food allergies, especially infants and children. Though, this fact is widely attributed to the changing livelihood of population in both developed and developing nations and to the introduction of new food habits with advent of novel foods and new processing techniques, their complete role is still uncertain. Under the circumstance, it is very important to understand the structural changes in the protein as food is processed to comprehend whether the specific processing technique (conventional and novel) is increasing or mitigating the allergenicity. Various modern means are now being employed to understand the conformational changes in the protein which can affect the allergenicity. In this review, the processing effects on protein structure and allergenicity are discussed along with the insinuations of recent studies and techniques for establishing a platform to investigate future pathway to reduce or eliminate allergenicity in the population.

Effect of Thermal and High Electric Fields on Secondary Structure of Peanut Protein

This study evaluated the effect of the thermal and high electric field stresses on the secondary structure conformation of peanut protein using Fourier transform infrared spectroscopy. The amide I region between the wavelengths 1700–1600 cm–1 of the spectra were studied for different thermal and high electric field treatments. Within thermal treatments, both hot air roasting and microwave processing treatments were evaluated. Hot air treatments were performed at temperatures of 50, 75, and 100°C from 15, 30, and 45 min while the microwave treatments were conducted at the same temperatures, but for 5, 10, 15, and 20 min. Three experimental conditions were evaluated for the electric field intensity of 10, 15, and 20 kV for 60, 120, and 180 min. Changes were observed at 1654–1650 cm–1, indicating conformational changes in the α-helix secondary structure. Similar changes were observed at various other wavelengths indicating changes in the 3/10 helix, β-sheets and random coils present in the protein. With an increase in the treatment time, the secondary structure reorganizations increased with the creation of new random coils and aggregated strands. Curve-fitting using Gaussian band shapes further supported the observations. In vitro protein digestibility studies were also performed and the protein changes also supported the observations from the spectra.

Effect of High Electric Field on Secondary Structure of Wheat Gluten

The effect of a high electric field on secondary structure conformation of fully hydrated (45.65% wet basis) gluten protein was studied by Fourier transform infrared spectroscopy. Three experimental conditions were evaluated including electric field intensity of 0 kV (no treatment), 3.5 kV, and 7kV and treatment time of 30, 60, and 90 min. Fourier transform infrared spectra of treated and non-treated hydrated gluten protein revealed that high electric field treatment resulted in irreversible changes in the secondary structures. For the 30 min treatment no variation was observed for electric field intensities 0 and 7 kV; but at 3.5 kV it showed slight reorganization and structural conversion of secondary structures. No variation in spectral pattern was observed for all the high electric field treatments for 60 min but major secondary structure reorganization took place for high electric field treatment at 90 min. Curve-fitting using Gaussian band shapes and principal component analysis further supported the results.

Electrohydrodynamic Drying of Sand

ABSTRACT This study analyzes the electrohydrodynamic (EHD) drying characteristics of sand. Effect of process parameters (independent variables) including air speed, electrode gap, and applied voltage on drying kinetics and dependent variables including percentage water removed (%), Sherwood number, EHD number, and specific energy consumed (SEC) (kJ/kg) were also investigated using a central composite design and response surface methodology. Maximum drying was obtained for process parameter combination of air speed (2 m/s), electrode gap (1.5 cm), and applied voltage (15 kV). Air speed and electric field intensity (ratio of applied voltage to electrode gap) were found to have a significant effect on percentage water removed (%) and Sherwood number. In case of EHD number and SEC during the EHD drying process, all process parameters had a significant effect on them. The SEC increased with an increase in applied voltage but reduced with an increase in air speed at any given applied voltage suggesting that the EHD drying process, in combination with cross flow, will lead to higher drying rate and low energy consumption under ambient conditions. Regression models were also developed describing the relation between independent and dependent variables.

Processing effects on tree nut allergens: A review

ABSTRACT “Tree nut” is a broad term for classification of nuts that include cashews, almonds, hazelnuts, etc. Reports of mild to adverse immune reactions following the consumption of these nuts has been on a rise in recent years. Currently, about 1.2–2% of the worlds population suffer from sensitivity to tree nuts. The only solution is complete abstinence from the allergy causing tree nut which is not feasible in most cases due to issues like cross contamination or their presence in the form of hidden ingredients in processed foods. Various studies have shown that food processing can effectively vary the secondary structures of the allergenic protein which in turn influences their functional properties. But, the impact of these processing methods on tree nuts allergens is mixed. This review gives an update on the recent findings on how conventional and novel processing methods influence the tree nut allergens.

How well do plant based alternatives fare nutritionally compared to cow’s milk?

AbstractDue to the issues like lactose intolerance and milk allergy arising from the consumption of cow’s milk, there has been an increased demand in the plant based alternative milks around the world. Food industry has addressed these demands by introducing various milk beverages which are promoted as alternatives coming from plant sources which include almond milk and soy milk. Though they are popularly advertised as healthy and wholesome, little research has been done in understanding the nutritional implications of consuming these milk beverages in short term and long term. Further, consumers associate these alternatives to be a direct substitute of cow’s milk which might not be true in all cases. This review tries to address the issue by outlining the differences between cow’s milk and commercially available alternative milks in terms of their nutrient content. Though various plant based alternate milks have been studied, only the four most consumed milk beverages are presented in this review which are consumed widely around the world. A complete nutritional outline and the corresponding health benefits of consuming these plant based milk beverages have been discussed in detail which could help the consumers make an informed decision.

Comparison of Conventional and Microwave Treatment on Soymilk for Inactivation of Trypsin Inhibitors and In Vitro Protein Digestibility

Soymilk is lower in calories compared to cow’s milk, since it is derived from a plant source (no cholesterol) and is an excellent source of protein. Despite the beneficial factors, soymilk is considered as one of the most controversial foods in the world. It contains serine protease inhibitors which lower its nutritional value and digestibility. Processing techniques for the elimination of trypsin inhibitors and lipoxygenase, which have shorter processing time and lower production costs are required for the large-scale manufacturing of soymilk. In this study, the suitable conditions of time and temperature are optimized during microwave processing to obtain soymilk with maximum digestibility with inactivation of trypsin inhibitors, in comparison to the conventional thermal treatment. The microwave processing conditions at a frequency of 2.45 GHz and temperatures of 70 °C, 85 °C and 100 °C for 2, 5 and 8 min were investigated and were compared to conventional thermal treatments at the same temperature for 10, 20 and 30 min. Response surface methodology is used to design and optimize the experimental conditions. Thermal processing was able to increase digestibility by 7% (microwave) and 11% (conventional) compared to control, while trypsin inhibitor activity reduced to 1% in microwave processing and 3% in conventional thermal treatment when compared to 10% in raw soybean.

Microencapsulation of hazelnut oil through spray drying

ABSTRACT This study was performed to investigate the influence of air inlet temperature (AIT) on the microencapsulation of hazelnut oil by spray drying. Encapsulated powders were analyzed for moisture content, powder yield, surface oil, encapsulation efficiency (EE), bulk density, and particle morphology. The obtained results demonstrated that moisture content, surface oil, and bulk density decreased by 37.8, 27.5, and 33%, respectively as AIT increased from 140 to 220°C. However, powder yield and encapsulation efficiency increased considerably with the rise in AIT. Higher EEs of about 75–80% were observed in this study.

Significance of fruit and vegetable allergens: Possibilities of its reduction through processing

ABSTRACT Fruit and vegetable allergies are prevalent commonly in adults, infants, and children all around the world, but more importantly in Europe and North America. The only solution is complete abstinence from the responsible food, which can be very difficult due to their presence in the form of hidden or undeclared ingredients. Various studies have shown the direct effect of processing on the secondary structure of proteins that can mitigate the allergic properties. The impact of these processing techniques on fruit and vegetable allergies have shown limited success due to the fact that they have multiple allergens that are especially heat stable. Apples, kiwi, peach, and melons are common fruits, whereas celery and carrot are the common vegetables that can result in allergic reactions for some portion of the population upon exposure. Abbreviations: IgE: immunoglobulin E, OAS: oral allergy syndrome, nsLTP: nonspecific lipid transfer proteins, LTP: lipid transfer proteins, HPP: high-pressure processing, PEF: pulsed electric field, CD: circular dichroism, pI: isoelectric point, DBPCFCs: double-blind placebo-controlled food challenges

Application of molecular dynamic simulation to study food proteins: A review

ABSTRACT This review presents an overview of the application of molecular dynamic simulation to study food proteins. Processing of food using thermal, chemical, radiation, electromagnetic, and mechanical techniques is subject to its macromolecular bio-components such as carbohydrates and proteins to extreme heat, ionic strength, pH, and mechanical deformation. These processing factors affect protein’s functional properties such as emulsification, dough formation, gelation, etc., which are associated with changes in their structure. It is difficult to study the structural changes of protein during processing using standard methods like Circular dichroism, Nuclear Magnetic Resonance (NMR), and X-ray diffraction. Hence, in this manuscript application of molecular dynamic simulation to visualize and analyze the protein dynamics during processing has been evaluated. Effect of external stresses such as hydration, temperature, and electric field on protein structure have been analyzed and related mechanisms are explained. The response of food proteins to these stresses demonstrated that it is necessary to gain insight into protein dynamics to be able to develop novel and/or modify existing food processing techniques to improve the overall nutritional and organoleptic qualities of processed food products.