Recent studies on alternative technologies for deep-fat frying.

Deep fat fried food products have been considered as a vital dietary contributor to certain chronic diseases, including the risk of atherosclerosis, cancer and hypertension. Hence, many food industries are focusing on low fat fried products to attract consumers. In general, oil is absorbed during deep fat frying, and this century old process is used for preparing various kinds of fried food products such as potato chips, banana chips, savory snacks, etc. Vacuum frying, electric field frying and two-stage frying technologies have been developed as an alternatives to traditional frying. These two technologies are suitable for most fried products; however, they may not be suitable for sugar based fruits as they can lead to the formation of browning reactions, which are generally considered unacceptable. This review aims to cover recent work done in the area of vacuum frying and two-stage frying, including the role of pre-treatment and post-treatment novel methods. Additionally, emphasis has been given on recent innovations to improve the quality of vacuum and two-stage frying, particularly concerning the reduction of oil uptake in fried food products.

Hydration behavior and kinetic studies of paddy cultivars: optimization of process variables for improved physical, milling and textural properties.

The optimization of hydration temperature and duration were determined in six basmati and non-basmati paddy cultivars varying in grain size, shape, and amylose content based on kinetic parameters and effect of hydration temperature on physical, milling, textural and color attributes. Based on higher R2, lower Chi square and RMSE values, Peleg model fitted more suitably compared to Singh and Kulshrestha model. Hydration process significantly altered geometric, gravimetric and mechanical properties as evident by regression analysis. Physical properties except length and L/B ratio positively correlated with increasing hydration temperature. Head rice yield significantly improved in the hydrated treatments and showed a linear increase with the increase in hydration temperature. Head rice yield significantly correlated with hardness of grain (r = 0.684, p ≤ 0.01). Variable physico-chemical properties of cultivars led to establishment of cultivar specific optimum hydration temperature. Based on improvement in hardness, milling efficiency, head rice yield, color and textural attributes, the optimized temperature emerged as 75 °C for long slender grained cultivars (PB1509, PB1718, PS17) and 80 °C for medium grained cultivars (PD18, KJ, AL). The results revealed that optimum hydration temperature should be cultivar specific to get better output of parboiling process. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-024-05925-1.

Effect of salt pretreatments on physico-chemical, cooking and rehydration kinetics of instant rice.

Instant rice is well-suited for ready-to-use applications as low-moisture, light-weight military ration and emergency food for our Armed Forces, offering longer shelf life with rapid rehydration characteristics. Present investigation demonstrated the effect of different salt pretreatment during soaking as precooking operation on the physico-chemical, cooking and rehydration kinetics of instant rice. Application of salt pretreatment reduced bulk density and damaged grain percentage, while enhanced the porosity, volume expansion percent, weight gain percentage, and rehydration characteristics. The grain elongation ratio was not affected significantly by the application of salt pretreatments; however, water uptake and chemical composition were significantly affected. Soaking pretreatment with 1% calcium chloride, followed by open pan cooking and subsequently freeze-thaw-dehydrating until attainment of 5-6% moisture content was found to be the optimal processing condition for developing instant rice with less than 2 min of rehydration time by mere addition of hot water. Modelling of water absorption behaviour revealed that both Peleg (R2 0.980-0.999) and Singh and Kulshrestha (R2 0.966-0.999) models fitted well. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-023-05877-y.

Kinetic study of thermal degradation of flaxseed oil and moringa oil blends with physico-chemical, oxidative stability index (OSI) and shelf-life prediction.

The thermal degradation kinetics of flaxseed oil (FSO) and moringa oil (MO) blends with soyabean oil (SOY; 80%), rice bran oil (RBO; 80%), cotton seed oil (CSO; 80%) and sunflower oil (SFO; 80%) with Rancimat equipment. There was no significant (p ≤ 0.05) difference observed in the specific gravity (SG), density (D), and refractive index (RI) values of the MO and FSO blends, while the rancidity parameters showed the opposite variations. The FTIR spectra showed absorption bands at 966 cm-1, 1097 cm-1, 1160 cm-1, 1217 cm-1, 1377 cm-1, 1464 cm-1, 1743 cm-1, 2945 cm-1, 2852 cm-1 and 3008 cm-1. Oil blends' kinetic degradation (Ea, ΔH, ΔS, A) is represented by the semilogarithmic relationship between the oxidative stability index (OSI) and temperature. The activation energy (Ea) ranged from 77.1 ± 0.21 to 106.9 ± 0.03 kJ/mol and 73.2 ± 0.01 to 104.4 ± 0.02 kJ/mol for flaxseed oil (FSO) and moringa oil (MO) blends, respectively. The enthalpy (ΔH) and entropy (ΔS) ranged from 67.3 to 121.6 kJ/mol, and - 60.2 to - 8.4 J/mol, and 63.55 to 95.59 kJ/mol and - 20.66 to - 4.11 J/mol for FSO blends and MO blends, respectively.

Influence of processing on bioactive compounds, Type-II diabetes related enzyme regulation potential and antiurolithiatic potential of underutilized legume Macrotyloma uniflorum.

The hydro-alcoholic extract of raw and processed Macrotyloma uniflorum seeds, an underutilized food legume was analysed for its bioactive compounds, Type-II diabetes enzyme regulation and antiurolithiatic potential. The study aimed to establish and promote the introduction of these new grains and enlarge the market of novel functional foods. The seed extract had phenolic content of 35.6 and 30.4 mg GAE/g dm, for PAIYUR-2 and GPM-6 respectively. Chlorogenic, coumaric, vanillic and ellagic were the major and, sinapic and syringic were limiting phenolic acids. The raw seeds extract exhibited ferric ion reducing potential (1125 and 1236 mmol Fe II/mg extract dm), free radical inhibition (EC50, 3.58 and 3.78 g dm/g DPPH), hydroxyl ion inhibition (46.71 and 45.44%) and superoxide ion inhibition (36.93 and 33.37%) for PAIYUR-2 and GPM-6 respectively. Further, considerable α-amylase (49.34 & 45.89%) and α-glucosidase (62.72 & 60.33%) inhibition potentials were observed along with antiurolithiatic activity of 48.12 and 46.31% in PAIYUR-2 and GPM-6 respectively. Although, processing had significant (p ≤ 0.05) impact on grain quality but still the significant (p ≤ 0.05) functional properties were retained. This proves the grain utility as a functional food in maintaining human health.

Development of instant paneer type product from groundnut using microwave dehydration.

The present study aimed at the development of a groundnut-based dehydrated paneer type product which could serve as an instant vegan protein source. In the process of preparing groundnut paneer, a ratio of 1:5 of groundnut to water and 2.0% calcium chloride (CaCl2) solution was used for the preparation of groundnut paneer and the product was evaluated for physicochemical, instrumental color, instrumental textural, and sensory characteristics. The developed paneer cubes (1.5 × 1.5 × 1 cm) were dehydrated using a vacuum-assisted microwave dryer at different microwave powers (200-600 W, 250 mbar vacuum). The minimum bulk density (0.55 g/cc) and maximum rehydration ratio (2.9) were recorded in the sample dehydrated at 600 W. The samples dried at 600 W also showed significantly (p < .05) higher L* values, softer texture and high sensory scores for color, aroma, taste, texture, and overall acceptability after rehydration.

Development of magnetic nanoparticle assisted aptamer-quantum dot based biosensor for the detection of Escherichia coli in water samples.

The contamination of food and potable water with microorganisms may cause food-borne and water-borne diseases. The common contaminants include Escherichia coli (E. coli), Salmonella sp. etc. The conventional methods for monitoring the water quality for the presence of bacterial contaminants are time-consuming, expensive, and not suitable for rapid on-spot detection in field conditions. In the current study, super paramagnetic iron oxide nanoparticles (SPIONs) were synthesized and conjugated with E. coli specific Aptamer I to detect E. coli cells qualitatively as well as quantitatively. The sludge consisting of E. coli- SPION complex was separated via magnetic separation. The presence of E. coli cells was confirmed with the help of standard techniques and confocal laser scanning microscopy (CLSM) employing Aptamer II conjugated CdTe-MPA quantum dots (QDs). Finally, an ATmega 328P prototype biosensor based on Aptamer II conjugated CdTe MPA QDs exhibited quantitative and qualitative abilities to detect E.coli. This prototype biosensor can even detect low bacterial counts (up to 1 × 102 cfu) with the help of a photodiode and plano-convex lens. Further, the prototype biosensor made up of ultraviolet light-emitting diode (UV LED), liquid crystal display (LCD) and ATmega328Pmicrocontroller offers on-spot detection of E.coli in water samples with high resolution and sensitivity. Similarly, this in-house developed prototype biosensor can also be utilized to detect bacterial contamination in food samples.

Impact of pulsed electric field processing on reduction of benzylpenicillin residue in milk.

PURPOSE: The presence of residues of veterinary drugs in animal-derived food is one of the major problems for food safety. The consumption of milk containing antibiotic residues can evoke allergic reactions in hypersensitive individuals, disorders of intestinal flora and produces the risk of emerging antibiotic resistance microorganism. METHODS: In this study, the effect of the thermal treatments and pulsed electric field (PEF) on the reduction of benzylpenicillin (PNG) spiked artificially in milk was evaluated quantitatively by calculating the loss of the concentration using HPLC. Fresh raw milk was subjected to a high-temperature short-time (72 °C for 15 s, HTST), low-temperature long- time (62.5 °C for 30 min, LTLT) and ultrahigh-temperature processing (138 °C for 2 s, UHT). The PEF process factors output voltage (20-65%) and pulse width (10-26 µs) were optimized for maximum reduction of PNG by employing the statistical tool response surface methodology (RSM). RESULTS: HTST, LTLT, and UHT have resulted in the reduction of PNG 13.5%, 6.1%, 1.2% respectively. The optimized parameters of the PEF treatment had reduction efficiency in the range of 79-86%. The saddle response surface obtained from RSM showed that the center was neither at maximum point nor at the minimum point. The predicted and experimental values of the response were nearly similar which proved the suitability of the fitted quadratic model. Combined thermal and PEF treatment has a significant synergistic effect in reducing the PNG. CONCLUSIONS: PEF induced reduction efficiency achieved was 79-86%. The reduction percentages were observed higher in the combined pasteurization and PEF treatment of milk. The pulsed electric field can be adopted as a unique processing tool for degradation of antibiotic residues whilst retaining nutritional quality parameters.

Physical modification of starch: changes in glycemic index, starch fractions, physicochemical and functional properties of heat-moisture treated buckwheat starch.

Native buckwheat starch was extracted and modified by heat-moisture treatment (HMT) with different treatment time (15, 30 and 45 min) to investigate its effect on physicochemical, morphological, functional properties, starch profile (rapidly digestible starch, RDS; slowly digestible starch, SDS and resistant starch, RS fractions) and expected glycemic index (eGI). Results revealed that with increasing time duration of HMT from 15 to 45 min, amylose content, pasting temperature and thermostability increased substantially whereas swelling power, solubility and viscosity parameters decreased. The SEM micrographs showed that HMT caused fissures in the granule and surface indentation. HMT-45 (starch treated for 45 min) had the lowest RDS content (29.33%) and the highest SDS (51.30%) and RS (8.21%) levels. The decreased hydrolysis rate, high amylose and RS content of HMT-45 resulted in a significant decrease in estimated glycemic index (eGI) values from 51.49% (Native) to 44.16% (HMT-45) thus indicating its role in prevention of non-insulin- dependent diabetes.

Engineering properties of horse gram (Macrotyloma uniflorum) varieties as a function of moisture content and structure of grain.

The study was conducted to determine the engineering properties of horse gram varieties namely GPM-6, PAYIUR-2, and BHK as a function of moisture content in range of 10-30%. The average length, width, thickness, geometric mean diameter, arithmetic mean diameter, thousand kernel weight, sphericity, porosity and angle of repose ranged from 5.43 to 6.53 mm, 3.96 to 4.48 mm, 2.21 to 2.99 mm, 3.62 to 4.41 mm, 3.86 to 4.64 mm, 30.32 to 49.11 g, 63.56 to 72.66%, 35.20 to 38.76% and 22.72° to 29.86° respectively as the moisture content of the grain increased from 10.08 to 29.98%. The bulk density and true density of the grain decreased from initial range of 810-901 to 734-801 kg m-3 and 1250-1426 to 1168-1308 kg m-3. The volume, porosity and terminal velocity of the grain increased linearly with increase in moisture content. The coefficient of friction also showed positive correlation for all surface materials, the highest increase was found for plywood in all varieties of horse gram seeds. Dehulling properties of the grain found to be significantly affected by the change in moisture content. The overall dehulling ranged from 53.44 to 61.21% for GPM-6 and 55.58 to 61.06% for PAYIUR-2 variety of horse gram. Textural properties of the grains were also found to be significantly affected by the change in moisture content from 10 to 30%. The data generated in this study will be highly useful in optimization of post-harvest processing operations as well as to design and develop related processing equipment for horse gram.

Optimized production of poly (γ-glutamic acid) (γ-PGA) using Bacillus licheniformis and its application as cryoprotectant for probiotics.

Bacteria produce poly (γ-glutamic acid) (γ-PGA), a polymer of l- or d-glutamic acid, as a defense response and have gained importance due to their applications in food and pharmaceutical industry. In the present investigation, production of γ-PGA using cost-effective carbon substrate, characterization of the produced polymer, and its application as cryoprotectant for selected freeze-dried probiotic bacteria were investigated. Central composite rotatable design of response surface methodology was used to study the main and the interactive effects of medium components: rice bran and casein peptone concentration. Rice bran at 35% (w/v) and casein peptone at 7.5% (w/v) were found to be optimal at an initial pH of 7.5, and incubation temperature of 37°C for 48 H produced 8.2 g/L γ-PGA on dry weight basis. The thermal properties such as melting temperature, heat of fusion, and thermal stability were also studied. Ten percent (w/v) of γ-PGA with 10 percent of sodium alginate (w/v) protected viability of Bifidiobacterium bifidum NCDC 235 and B. adolescentis NCDC 236 during freeze drying at -80 ËšC for 48 H. The γ-PGA synthesized by the reported bacterium with GRAS status is suitable for food and biomedical applications.

Development and storage stability of buckwheat chips using response surface methodology (RSM).

Processing conditions (potato level, frying temperature and frying time) were optimized for the development of buckwheat based chips using response surface methodology (RSM). Moisture content, oil uptake, color values, hardness and overall acceptability (OAA) were used as indices of product quality. The polynomial regression model was fitted with R2 values of 0.983, 0.982, 0.98, 0.996, 0.973, 0.984 and 0.985 for moisture content, oil uptake, L, a*, b* values, hardness, and OAA respectively indicating fitness of the models. Potato level and frying temperature showed a significant effect on all responses at linear and quadratic levels except frying temperature for OAA at the linear level and hardness at quadratic level. Frying time showed significant effect on a* value, b* value, hardness and OAA at linear level. Interaction between all processing variables had a significant effect on a* value. Interaction between potato level and frying temperature had significant negative effect on moisture content of buckwheat chips. Potato level (30%), frying temperature (169 °C) and frying time (51 s) were found to be the optimum processing conditions with maximum OAA (8.36). 0.33 aw was established as the water activity at which maximum stability of chips was shown. Buckwheat chips packed in both polypropylene (PP) and metallised polyester (MP) remained stable and acceptable for 6 months at RT whereas for 3 and 6 months in PP and MP films respectively at 37 °C.

Melting, crystallization and storage stability of virgin coconut oil and its blends by differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR).

The blends were prepared of virgin coconut oil with refined soyabean oil (VCO-RSOY) and refined safflower oil (VCO-RSAFF). Blending with VCO improved the fatty acid composition which increased the shelf stability of 20:80 VCO-RSOY and VCO-RSAFF up to 12 months in different packaging systems such as low density polyethylene, linear low density polyethylene, metalized polyester pouches, polyethylene teteraphthalate, high density polyethylene (HDPE), Amber HDPE bottle. The specific spectral regions of FTIR proved to be very useful for the determination of adulteration as well as for the study of oxidation process. Band shifts observed at 3008, 1652, 1397, 1097, 912 and 845 cm-1 have been used to differentiate RSAFF from VCO. VCO spectrums did not have these chemical shifts. Further the spectrum of RSOY showed same band shifts as RSAFF except 1652, 1397, 869.6 and 845 cm-1. Differential Scanning Calorimetry provided useful information regarding the nature of thermodynamic changes related to physical state of vegetable oil. The physical state changes included melting and crystallization events which require the intake and release of energy.

Effect of virgin coconut meal (VCM) on the rheological, micro-structure and baking properties of cake and batter.

Virgin coconut meal (VCM) cakes were prepared by replacing refined wheat flour (maida) (5 to 20 % level) to check its effect on chemical, textural and rheological attributes of cake. The addition of VCM significantly (p ≤ 0.05) increased redness (a*), yellowness (b*) while reduced lightness (L*) of cakes. The incorporation of VCM affects the hardness, adhesiveness gumminess and chewiness of cake. The effect of flour replacement with VCM increased the viscosity of batter which leads to increase in consistency index and lower the shearthining behavior. The viscoelastic behavior of cake batter in which elastic modulus (G') and viscous modulus (G") both were decreased with the increase in percentage of VCM. The differential scanning calorimetry (DSC) analysis revealed that the onset (To), end set (Tc) and enthalpy of gelatinization (ΔH) increased with the increased level of VCM.

Effect of spinach powder on physico-chemical, rheological, nutritional and sensory characteristics of chapati premixes.

Effect of spinach powder on the physico-chemical, rheological, nutritional and sensory characteristics on chapati premixes was studied by incorporating spinach powder at different concentrations from 1 % to 10 % based on wheat flour. Addition of 5 % of spinach powder to wheat flour was found to be optimum for chapati preparation. Effect of incorporation of spinach powder on the alveo-consistographic, mixographic and pasting characteristics were studied. It was observed that peak viscosity, breakdown viscosity significantly decreases whereas, peak time, tenacity increases with the increase in the concentration of spinach powder from 1 % to 10 % in chapati premixes. Addition of spinach powder also significantly affects the textural qualities of the chapaties. Premixes and prepared chapaties were also studied for chlorophyll content, total carotenoids,vitamins and minerals.

A study on monitoring of frying performance and oxidative stability of virgin coconut oil (VCO) during continuous/prolonged deep fat frying process using chemical and FTIR spectroscopy.

The performance or quality of the Virgin coconut oil (VCO) during continuous/prolonged deep fat frying of soaked bengal gram dhal was evaluated at 180 °C ± 5 °C for 8 h with the help of physico-chemical and rheological parameters. Chemical changes indicated that the free fatty acid (FFA) content and TBA increased significantly (p ≤ 0.05) from 0.11 to 0.98 % lauric acid and 0.06 to 0.61 malonaldehyde/kg of oil respectively. Initially, the peroxide value (PV) of VCO sample was 3.25 meqO2/kg which increased to 9.12 meqO2/kg after 6 h of frying but at the end of frying the value of PV was again found to decrease (8.01 meqO2/kg). The regression coefficients (R(2)) between CD232, CT270 and frying time were 0.964 and 0.983 respectively. The L*, a* and b* colour values measured on the CIELAB colour scale showed a decrease in L* and increase in a*, b* values after 8 h of continuous frying. The p-AV and total polar compounds were increased significantly (p ≤ 0.05) from 2.41 to 17.93 and 2.77 to 8.14 % respectively. Initially, the viscosity of VCO was 49.87cp which increased to 69.87cp after 8 h of continuous frying. The FTIR spectra justify that VCO samples after 8 h of frying found to be stable and acceptable as there was no change occurred at 1,739 cm(-1) frequency which mainly corresponded to carbonylic compounds resulted from the hydroperoxide decompositions after 8 h of continuous frying.

Studies on the shelf-life enhancement of potato stuffed parotha using thermal processing.

Convenient, ready-to consume thermally processed potato stuffed parothas retaining their natural sensory attributes have been developed. Response Surface Methodology was used to optimize the Stuffing: dough ratio along with other ingredients. Optimized Stuffed parothas were packed in indigenously developed retortable pouches and processed in a steam-air retort. The time-temperature history was recorded during heat processing using an Ellab data cum Fo recorder. The total processing time was 25 min with a Fo value of 3.5. The quality of the developed product was evaluated chemically, sensorily and microbiologically to assess the shelf-life. After 12 months of storage, peroxide value (PV), thiobarbituric acid value (TBA) and free fatty acid value (FFA) increases significantly (p ≤ 0.05) from 9.98 to 29.16 meqO2/Kg fat, 0.101 to 0.171 mg MA/Kg sample and 1.01 to 2.66 % oleic acid respectively. The chemical changes and overall acceptability scores were found to be negatively correlated during storage. Textural and colour values also had an impact on the sensory scores of stuffed parothas during storage. After 12 months of storage, sensory scores decreases significantly (p ≤ 0.05) from 8.6 to 7.1 on a nine point hedonic scale. Microbiologically stuffed parothas remained stable during entire period of storage.