Differences In Quality Parameters Research Articles

Effect of different degumming methods on the chemical composition and physicochemical properties of tiger nut (Cyperus esculentus L.) oil

Abstract Objectives Tiger nut oil (Cyperus esculentus L.) is a promising edible oil rich in oleic acid. This study aimed to clarify the impact of different degumming methods on the chemical composition and physicochemical properties of crude tiger nut oil (CTO). Materials and Methods Five degummed tiger nut oils were prepared by high-temperature water (HWDO), medium-temperature water (MWDO), sodium chloride solution (SDO), acidic solution (ADO), and enzymatic method (EDO), respectively. Results Compared to CTO, the phospholipid contents of HWDO, MWDO, SDO, ADO, and EDO were reduced by 99.39%, 97.18%, 69.95%, 63.77%, and 65.60%, respectively. For CTO and all degummed oils, the fatty acid and endogenous antioxidant (i.e., tocopherols, sterols, flavonoids, total phenolics, and carotenoids) contents showed only small differences, but showed significant differences in quality parameters. Both the oxidative stability index and ferric ion reducing antioxidant power decreased significantly after degumming; the former from 52.26 to 15.55–19.80 h, and the latter from 5818.91 to 4348.73–4524.34 μmol TE/kg. Conclusions These changes are highly related to the removal of hydratable phospholipids. In short, EDO exhibited the lowest turbidity, while MWDO showed the best oxidative stability (19.80 h) and highest smoke point (230.0 °C). This information can be utilized to improve the industrial production of tiger nut oil.

Investigating the effects of surface water recharge on groundwater quality using hydrochemistry and ANFIS model: A case study Minia Governorate, Egypt

Monitoring and assessing groundwater quality and quantity lays the basis for sustainable management. Therefore, this research aims to investigate various factors that affect groundwater quality, emphasizing its distance to the primary source of recharge, the Nile River. To this end, two separate study areas have been considered, including the West and West-West of Minia, Egypt, located around 30 and 80 km from the Nile River. The chosen areas rely on the same aquifer as groundwater source (Eocene aquifer). Groundwater quality has been assessed in the two studied regions to investigate the difference in quality parameters due to the river's distance. The power of machine learning to associate different variables and generate beneficial relationships has been utilized to mitigate the cost consumed in chemical analysis and alleviate the calculation complexity. Two adaptive neuro-fuzzy inference system (ANFIS) models were developed to predict the water quality index (WQI) and the irrigation water quality index (IWQI) using EC and the distance to the river. The findings of the assessment of groundwater quality revealed that the groundwater in the west of Minia exhibits suitability for agricultural utilization and partially meets the criteria for potable drinking water. Conversely, the findings strongly recommend the implementation of treatment processes for groundwater sourced from the West-West of Minia before its usage for various purposes. These outcomes underscore the significant influence of surface water recharge on the overall quality of groundwater. Also, the results revealed the uncertainty of using sodium adsorption ratio (SAR), Sodium Percentage (Na%), and Permeability Index (PI) techniques in assessing groundwater for irrigation and recommended using IWQI. The developed ANFIS models depicted perfect accuracy during the training and validation stages, reporting a coefficient of correlation (R) equal to 0.97 and 0.99 in the case of WQI and 0.96 and 0.98 in the case of IWQI. The research findings could incentivize decision-makers to monitor, manage, and sustain groundwater.

Lyophilisation of bacterial test strains in a manifold-type apparatus: Effects of freezing and drying parameters, ampoule fill volume, and cotton filter density

Scientific relevance. Lyophilisation is the preferred method at the National Collection of Pathogenic Microorganisms (NCPM) of the Scientific Centre for Expert Evaluation of Medicinal Products of the Ministry of Health of the Russian Federation. Lyophilisation is used to provide for high standards of test-strain deposition, storage, and transportation and to ensure that test strains maintain their properties. Successful lyophilisation requires conducting experiments to establish the key parameters and critical conditions of the process.Aim. The study aimed to evaluate the effects that the speed and time of freezing, the time of drying, the fill volume of ampoules, and the density of cotton filters have on the quality of NCPM indicator microorganisms lyophilised in a manifold-type apparatus.Materials and methods. Pseudomonas aeruginosa NCTC 12924, Staphylococcus aureus NCTC 10788, and Salmonella Abony NCTC 6017 were freeze-dried using a manifold-type apparatus (M. S. R. 18, Usifroid). The authors used a low-temperature freezer at –70±2 °C for slow freezing and a mixture of dry ice and alcohol for quick freezing. The statistical analysis was performed using Microsoft Excel and Statistica 10.Results. The minimum time needed for freezing the samples in a low-temperature freezer at –70±2 °C was 4 hours. Further storage at this temperature for up to 1 month was shown possible without compromising the quality of the final product. The time needed for freezing the samples in a mixture of dry ice and alcohol was under 1 minute. No differences in quality parameters were observed between the lyophilised samples frozen slowly or quickly, except for the cake appearance. Quick freezing resulted in cakes that were non-uniform, crumbled, and pulled away from the ampoule walls, which is considered undesirable. The primary drying stage for ampoules with a fill volume of 0.2 mL took 6–8 hours. The secondary drying stage of 11, 18, 35, and 59 hours resulted in comparable lyophilisate quality: the authors observed no statistically significant differences in viable cell counts (CFU/mL) at the end of lyophilisation and at the end of stress testing. The residual moisture content after 59-hour secondary drying was less than 2%. The cotton filter density had a critical influence on the lyophilisate quality. Therefore, the authors recommend using cotton filters weighing 50 mg or less.Conclusions. The authors analysed the main stages of the lyophilisation process used for NCPM test strains and considered the effects that the speed and time of freezing, the time of drying, the fill volume of ampoules, and the density of cotton filters have on the quality of the final lyophilised product. The NCPM has implemented the results of this study in its work.

Are the Blueberries We Buy Good Quality? Comparative Study of Berries Purchased from Different Outlets.

Blueberries (Vaccinium corymbosum L.) are becoming increasingly popular for their nutritional and health benefits, and their economic value is therefore increasing. The loss of quality that can occur due to softening and fungal attack is an important consideration when marketing blueberries. Despite the added value of blueberries, no studies have been carried out on how the fruit arrives at the outlets just before purchase by the consumer in terms of firmness, physico-chemical parameters, phenolic compounds, and fungal growth. The aim of this work has been, therefore, to investigate possible differences in quality parameters between blueberries purchased from ten different outlets, regardless of the supplier. The results showed that all the samples were of acceptable quality, although they all had a low maturity index at the point of sale. None of the samples studied showed clear signs of fungal decay at the time of purchase, although we were able to grow and identify some pathogen specimens after cultivation. In terms of total phenolic and anthocyanin content, as well as antioxidant activity, all the samples showed low values, possibly due to their postharvest storage, but they were within the expected range for this fruit. On the other hand, differences in the measured parameters were observed between samples of the same cultivar while no differences were found between conventionally and organically grown blueberries. This suggests that preharvest (such as edaphoclimatic conditions, agricultural practices, and cultivars) and postharvest factors (such as treatments used, storage, and transport temperatures) could influence the berry quality when they reach the consumer.

The Efficacy of Different Mulching with Spacing on Growth and Yield of Strawberry (Fragaria ananassa Duch.) cv Chandler

An experiment was conducted at the Horticultural Research Farm of Babasaheb Bhimrao Ambedkar University, Lucknow. The experiment was performed to find out the most suitable mulching material and an ideal spacing for straw berry cultivation under Lucknow conditions. The experiment was laid out in a Factorial Randomized Block Design with three replications. The treatments comprised of three mulching materials viz. paddy straw, black polyethylene, and transparent polyethylene) with three spacings (30 x 15 cm and 30 x 20 cm and 30 x 30). On the basis of the statistical data, it is concluded that spacing of 30 x 30 cm with black polyethylene mulch was found to be the best in terms of plant growth viz. plant height, spread of plants, Number of flowers per plant, Number of leaves per plant, Fruit weight, Fruit length, Fruit diameter, Specific gravity of Fruit, and Fruit yield per plant, Fruit yield per plot, Fruit yield per plant and leaf area.However, there was slight difference in quality parameters among different treatments.The data recorded was significant difference in number of leaves per plant. Spacing 30x30 cm treatment S3 gave the maximum number of leaves per plant (19.17), which was statistically similar (18.66) to at 30x20 cm spacing, while 30x15 cm spacing gave the minimum number of leaves per plant (17.89).Different mulching showed significant differences on the number of leaves per plant. The maximum number of leaves per plant was recorded in (21.23) from black polythene mulch (M2) which was closely followed treatment (M3) and maximum number of leaves per plant was recorded in (15.79) M1 (Transparent polythene mulch).

Effects of Different Processing Methods of Coffee Arabica on Colour, Acrylamide, Caffeine, Chlorogenic Acid, and Polyphenol Content.

An effect of a processing method (dry and wet) and a degree of roasting (light, medium, and dark) of 15 coffee (Coffea arabica) samples on the content of caffeine, chlorogenic acid (CQA), total polyphenols (TPP), acrylamide (AA), and on the colour parameters L*, a*, and b* was evaluated. Neither processing nor roasting affected caffeine content (p > 0.05). The degree of roasting accounted for 46% and 72% of explained variability of the CQA content and AA content, respectively (p < 0.05). AA content was in the range from 250 (wet-processed, light-roasted samples) to 305 µg·kg−1 (wet-processed, dark-roasted coffees), but the dark roasting only tended (p > 0.05) to increase AA content. Wet-processed, dry-roasted coffee had higher (p < 0.05) TPP content (48.5 mg·g−1) than its dry-processed, dry-roasted counterpart (42.5 mg·g−1); the method of processing accounted for 70% of explained variability of TPP. Both the method of processing and the degree of roasting affected the L*, a*, and b* values (p < 0.01), but the lower values (p < 0.05) of these parameters in the dark-roasted samples were found only within the wet processing. A negative correlation between the AA content and lightness (L*) was established (r = −0.39, p < 0.05). It was concluded that from the consumers’ viewpoint, the results of the present study indicate relatively small differences in quality parameters of coffee irrespective of the method of processing or degree of roasting.

A Comparison of Fresh and Frozen Lamb Meat-Differences in Technological Meat Quality and Sensory Attributes.

Simple SummaryFreezing is used to extend the storage time of meat and is common practice in lamb meat production, since it maintains a steady supply of seasonal meat throughout the year and allows shipping over long distances. Fresh meat may also be purchased and frozen at home, to enable longer storage of the product before consumption. Freezing is the best preservation method, apart from chilling of fresh meat. However, differences in quality parameters between fresh and frozen meat may influence consumer choice and preferences. It is thus important to evaluate these differences, and how they are affected by conditions and animal handling during primary production, slaughter method and storage conditions before retail sale. This study examined the effect of freezing on technological meat quality and sensory attributes in lamb meat samples collected at two different slaughterhouses using different slaughter methods. Several differences between fresh and frozen-thawed meat were detected in terms of technological meat quality and sensory attributes, including colour, Warner-Bratzler shear force, cooking loss, flavour attributes and juicy texture.Technological meat quality and sensory attributes of fresh and frozen lamb meat were compared. Samples were collected from two abattoirs (one small-scale, one large-scale) that use different slaughter methods in terms of chilling regime and electrical stimulation. The fresh and frozen meat samples included products from both slaughter systems. Ten twin pairs of ram lambs were used in the study, with one of each twin slaughtered at each abattoir. Fresh meat was analysed after chilling and frozen meat was stored frozen for three months and analysed after thawing. The Musculus longissimus thoracis et lumborum was analysed for colour, cooking loss, sensory attributes, Warner-Bratzler shear force (WBSF) and distribution of water and lipid within each meat sample. Meat samples analysed after frozen storage were darker, less red and more yellow than the fresh meat. Freezing and frozen storage increased fluid loss and WBSF compared with the fresh meat, due to protein denaturation. Frozen storage affected sensory attributes by increasing fatty odour, frying flavour, sour flavour, fatty flavour and liver flavour, and by reducing juicy texture and mushy texture.

Evaluation of the Relationship between Freezing Rate and Quality Characteristics to Establish a New Standard for the Rapid Freezing of Pork.

This study evaluated the effect of freezing rate on the quality characteristics of pork loin to establish an objective standard for rapid freezing. To generate various freezing rates, three air flow rates (0, 1.5, and 3.0 m/s) were applied under three freezing temperatures (–20°C, –30°C, and –40°C). Based on the results, freezing rates ranged from 0.26–1.42 cm/h and were graded by three categories, i.e, slow (category I, >0.4 cm/h), intermediate (category II, 0.6–0.7 cm/h) and rapid freezing (category III, >0.96 cm/h). Both temperature and the air flow rate influenced the freezing rate, and the freezing rate affected the ice crystal size and shear force in pork loin. However, the air flow rate did not affect thawing loss, drip loss or the color of pork loins. In the comparison of freezing rates, pork belonging to category II did not show a clear difference in quality parameters from pork in category I. Furthermore, pork in category III showed fresh meat-like qualities, and the quality characteristics were clearly distinct from those of category I. Although the current standard for rapid freezing rate is 0.5 cm/h, this study suggested that 0.96 cm/h is the lowest freezing rate for achieving meat quality distinguishable from that achieved with conventional freezing, and further increasing the freezing rate did not provide advantages from an energy consumption perspective.

Comparative study on physicochemical, nutritional and enzymatic properties of two Satsuma mandarin (Citrus unshiu Marc.) varieties from different regions

Two Satsuma mandarin varieties (Miyagawa and Owari) from three typical cultivation regions in China (Zhejiang, Hubei, and Hunan province) were selected, and their physicochemical, nutritional, and enzymatic properties were comparatively studied. The results showed that Satsuma mandarin exhibited differences in quality parameters from both variety and region. From the principal component analysis (PCA), the samples were clearly distinguished. The L*, a*, b*, juice yield, titratable acidity (TA), total soluble solids (TSS), amino acid (AA), and carotenoid content of samples were more influenced by regions. The data obtained in this study will facilitate the characteristic evaluation of Satsuma mandarin and provide beneficial guidance for fruit processing.

Quality and Economics of Bt Cotton as Influenced by Compost, Organic and Inorganic Fertilisers

Agricultural application of urban waste as nutrient source for plants and as soil conditioner, is the most cost effective option of waste management because of its advantages over traditional means such as land filling or incineration. Composting is an attractive alternative of urban waste recycling. Intensive cropping and indiscriminate fertilizer application depleted available NPK in almost all soils in India. Hence, replenishment of shoveled out nutrients is very essential, especially when exhaustive crops like cotton is cultivated. With this backdrop an experiment was conducted during kharif, 2014 carried out at College Farm, College of Agriculture, PJTSAU, Hyderabad, India to find the effect of combined application of municipal city compost with inorganic fertilisers on the yield, quality and economics of Bt cotton. The experiment was laid out in randomised complete block design with three replicates and eleven treatments viz; 100 % NPK alone (RDF: 150: 60: 60 kg NPK ha-1)100% NPK + FYM (farmers practice) and 100 %, 75%, 50% NPK integrated with 3 levels of Godavari Gold (GG) @ 1.25, 1.875 and 2.5 tonnes ha-1 respectively. The results indicated that Bt cotton registered significantly higher yield attributes and yield with the integrated application of 100 % NPK + 2.5 t ha-1 of Godavari Gold compost as compared to 100% NPK alone, 100% NPK + FYM (farmers practice) and 75 % RDF (112.5-45-45 kg NPK ha-1) and 50 % RDF (75-30-30 kg NPK ha-1) integrated with Godavari gold compost @ 1.25, 1.875 and 2.5 tonnes ha-1.There were no significant differences in quality parameters. Highest gross, net returns and B: C ratio was accrued with the application of 100 % NPK + 2.5 t ha-1 of Godavari Gold compost.

Spatial and source disparities of groundwater quality in Dawakin-Tofa local government area of Kano State, Nigeria

The research assessed the spatial and source variations in groundwater quality in different locations and wells respectively across Dawakin-Tofa Local Government Area. The study area was divided into 10 by imposing a grid on its map and thereafter 10 hand dug wells and boreholes were selected, one from each location. Physical and chemical parameters like temperature, pH, Total Dissolved Solids (TDS) and heavy metals were tested in the laboratory and figures statistically compared with Nigeria’s national standard using ANOVA. The most notable difference in quality parameters between open wells and boreholes is in TDSs, electrical conductivity and chlorine content. The differences recorded in the other quality parameters ranged from between 0.0026 mg/l (in the case of lead) to 0.7°C (in the case of Temperature). This showed that the physio-chemical properties of open wells and boreholes are not much significantly different in the areas. The mean difference of TDSs between wells and boreholes in Dawakin-Tofa LGA is 35.721 mg/l, meaning that well waters are generally more turbid than that of boreholes which was not unexpected because of structural differences and modes of operation. While some quality parameters in Dawakin Tofa like TDSs, Electrical Conductivity, Temperature, Chlorine and Manganese content generally recorded non-harmful values as compared to the drinking standard; others like lead, chromium, cadmium recorded harmful values. Only Jalli (with above 300) and Tattarawa (with above 400) mg/l recorded TDS levels close to the maximum accepted limit of 500. This study further confirms the increased danger and risk of contaminated groundwater among consumer’s not only urban areas, but also in rural areas as well. Though, the levels of some elements like Sodium, Chlorine, Manganese and Magnesium in groundwater of Dawakin-Tofa LGA are currently within the National Acceptable limits, but the concentration of heavy metals clearly shows there is serious risk. Continuous monitoring, control and necessary policy decisions were recommended.

Effect of Zeolite Properties on Dewaxing by Isomerization of Different Hydrocarbon Feedstocks

Dewaxing by isomerization is one of the most important processes for base oil production of groups II and III. The core of this process is the isomerization of n-paraffins of the feed. While individual paraffin isomerization using different catalysts is thoroughly investigated in many research studies, the effect of zeolites and process conditions on dewaxing by isomerization of different real hydrocarbon feeds is less well known. In the presented work, ZSM-23 and SAPO-11 zeolite-based catalysts were prepared, characterized using different analytical techniques (X-ray diffraction, scanning electron microscopy, transmission electron microscopy, inductively coupled plasma atomic emission spectroscopy, N2-sorption, and NH3-TPD), and tested using dewaxing by isomerization of hydrocracked oil and petroleum wax under conditions close to those used in industry. Differences in quality parameters of dewaxed products obtained using different catalysts were also investigated. It was found that the ZSM-23-based catalyst was more active than the catalyst prepared using SAPO-11. While in dewaxing of hydrocracked oil both investigated catalysts showed similar product yields, in petroleum wax isomerization, a SAPO-11-based catalyst was more selective and showed greater yields of high-VI products. It was also established that using the SAPO-11-based catalyst led to dewaxed products with lower density, viscosity, and saturated hydrocarbon content compared with those obtained on the ZSM-23-based catalyst. Findings of this work can help researchers to develop more effective dewaxing catalysts for different hydrocarbon feeds.

Influence of the ethylene‐related signal‐inhibiting octapeptide NOP‐1 on postharvest ripening and quality of ‘Golden Delicious’ apples

Processes extending the shelf life of climacteric fruit play an important role in terms of a sustainable global food supply. In a previous study, a synthetic octapeptide (NOP-1) was shown to inhibit the interaction between ethylene receptor (ETR) and ethylene insensitive-2 (EIN2), and in consequence delay tomato ripening. We investigated for the first time the effect of NOP-1 on inhibiting the ripening of apples ('Golden Delicious') during postharvest. Using purified recombinant proteins from a bacterial expression system, we demonstrate here that EIN2 also interacts tightly (Kd = 136 ± 29 nmol L-1 ) with the corresponding apple ETR MdETR1. In line with previous binding studies on tomato ETRs, the ripening-delaying peptide NOP-1 clearly binds to the purified apple ETR. An NOP-1 solution (1000 µmol L-1 ) was applied with a brush or microdispenser and compared with apples treated with 1-methylcyclopropene (1-MCP) (SmartFresh™, Agrofresh) applied as gaseous treatment or untreated control fruits. NOP-1 inhibited colour development and chlorophyll degradation during shelf life. These effects were more pronounced with the brush application (surface film) than with microdroplets application (mimicking a sprayable formulation). NOP-1 did not alter ethylene release or respiration rate, whereas 1-MCP expectedly strongly suppressed both. There were no differences in quality parameters evaluated. Our study shows that NOP-1 binds to MdETR1 which results in delaying of ethylene-dependent ripening developments of skin colour and chlorophyll. Besides application methods, possible reasons for the weak effect of NOP-1 in comparison with previous tomato experiments could be different receptor affinity and penetration differences. © 2019 Society of Chemical Industry.

Natural Ecosystem Surrounding a Conventional Banana Crop Improves Plant Health and Fruit Quality.

Natural ecosystems near agricultural landscapes may provide rich environments for growing crops. However, the effect of a natural ecosystem on crop health and fruit quality is poorly understood. In the present study, it was investigated whether the presence of a natural ecosystem surrounding a crop area influences banana plant health and fruit postharvest behavior. Plants from two conventional banana crop areas with identical planting time and cultural practices were used; the only difference between banana crop areas is that one area was surrounded by a natural forest (Atlantic forest) fragment (Near-NF), while the other area was inserted at the center of a conventional banana crop (Distant-NF). Results showed that bananas harvested from Near-NF showed higher greenlife and a more homogeneous profile during ripening compared to fruits harvested from Distant-NF. Differences in quality parameters including greenlife, carbohydrate profile, and pulp firmness between fruits harvested from Near-NF and Distant-NF are explained, at least partly, by differences in the balance of plant growth regulators (indole-3-acetic acid and abscisic acid) in bananas during ripening. Furthermore, plants from Near-NF showed a lower severity index of black leaf streak disease (BLSD) and higher levels of phenolic compounds in leaves compared to plants from Distant-NF. Together, the results provide additional evidence on how the maintenance of natural ecosystems near conventional crop areas could be a promising tool to improve plant health and fruit quality.

Differences in quality parameters and nutrient composition in Fukumoto oranges with and without creasing symptoms

ABSTRACTCreasing is a physiological disorder in oranges fruits that affects rind quality. This disorder has been associated with insufficient or imbalances of nutrients in the fruit. A study was carried out in an orange orchard cv. Fukumoto. At harvest, fruit samples were selected with and without creasing, according to visual symptoms. External and internal fruit quality was evaluated in whole fruit, then dry matter and mineral content and concentration (nitrogen N, potassium K, calcium Ca and magnesium Mg) was analyzed in flavedo, albedo and pulp. Oranges with creasing had larger weight and fruit size, higher water content in the pulp and whole fruit, lower coarse rind grading, thinner peel, higher nitrogen content in the pulp and the whole fruit, higher potassium content in all fruit components and lower calcium content and concentration. Magnesium content, only in flavedo showed significant differences, being higher in fruit without creasing. Fruit size and Ca were key factors related to the expression of creasing disorder, as well as nutrient balance.

Quality parameters of currant berries from three different cluster positions

The challenge in the production of currants is the definition of the optimum harvest time due to successive ripening of berries over the entire length of cluster. The study focused on detecting the differences in quality parameters among individual positions of berries in the cluster. A red, black and white currant cultivar (‘Rovada’, ‘Tsema’ and ‘Blanka’) were selected for the experiment as they all develop long clusters and are used for fresh consumption. The berry mass, colour parameters and pH of the juice were recorded and sugar and organic acids contents were determined using HPLC. A detailed analysis of individual phenolic compounds was performed on HPLC–MS. The results of the study indicate that berries from the basal part of the cluster contain higher levels of sugars, organic acids and vitamin C in comparison with berries positioned at apical cluster sections. A similar pattern was observed for phenolic components: berries of the ‘Rovada’ cultivar contained almost twice the amount of total anthocyanins (TA) in berries from the basal cluster section compared to berries positioned at the apical part of the cluster. The differences were even more prominent (2.8 fold more TA in basal cluster section) in black currant ‘Tsema’. Significant differences in the content of all identified phenolic groups have been determined between the basal and apical position of berries in the cluster: berries from the basal part contained from 1.6 to 2.2 fold more hydroxycinnamic acids, from 1.7 to 2.2 fold more flavonol glycosides and from 1.5 to 1.8 fold more flavanols (catechin, epicatechin and procyanidin). The results of the study may be useful to the producers who strive to improve their production technology, for food and processing industry and for consumers as it was pointed out that the quality of berries at the apical part of the currant clusters is decreased compared to berries from the basal part of the cluster.

Quality of bread baked from frozen dough – effects of rye, and sugar content, kneading time and proofing profile

Abstract The objectives of this study were to evaluate whether proofing profile influences volume and crumb firmness in bread baked from frozen dough, and whether rye or sugar content and different kneading times affect the microstructure of the frozen dough. Microscopy was used to explain the differences. Wheat doughs mixed with rye (“rye”) and with sugar (“sweet”) were frozen after 3 different proofing times (0, 18, and 38 min) and visualized with confocal laser scanning microscopy and 3-dimensional micro-computed tomography. The baked breads were evaluated for volume and texture. Breads from un-proofed frozen dough allowed to proof after thawing showed the highest volume (4.0 cm3/g) and the softest crumb texture. The pre-proofed sweet bread had firmer crumbs and lower volume (2.5–3.0 cm3/g) than the pre-proofed rye bread (2.7–3.7 cm3/g). Reasons for the differences in quality parameters between the rye and sweet breads were investigated by studying the different influences of kneading time and sugar content on fresh and frozen dough. The gluten network was found to be more homogeneously distributed in doughs with longer kneading times and lower sugar content, and less well distributed and more lumped in frozen than in fresh dough.

Verification of radio frequency heating uniformity and Sitophilus oryzae control in rough, brown, and milled rice

Radio frequency (RF) heating is considered to be an alternative physical method for disinfesting postharvest agricultural products to replace chemical fumigation due to its inherent dangers on human health and environment. A pilot-scale, 27.12 MHz, 6 kW RF system was used to study the RF heating uniformity and validate the developed RF treatment protocols for disinfesting rough, brown, and milled rice. The results showed that the optimum RF heating uniformity in rough and brown rice was obtained by an appropriate electrode gap of 11 cm with a forced hot air heating at 50 °C, movement of the conveyor with a speed of 12.4 m/h, two mixings, and holding at 50 °C hot air for 5 min. Mortality of adult rice weevils, Sitophilus oryzae (L.), increased with increasing heating temperature and holding time, and reached 100% while RF heating at 50 °C holding in hot air for at least 6 min. There were no significant differences in quality parameters (moisture, protein, water activity, starch, free fatty acid, ash, and color) between RF treatments and untreated controls during storage (P > 0.05). The developed non-chemical alternative RF technology may hold potential for disinfesting rough, brown, and milled rice required by the growing organic market.

Selection for muscle fat content and triploidy affect flesh quality in pan-size rainbow trout, Oncorhynchus mykiss

A lean muscle line (L) and a fat muscle line (F) of rainbow trout were established (Quillet et al., 2005) by a two-way selection for muscle lipid content performed on pan-size rainbow trout using a non-destructive measurement of muscle lipid content (Distell Fish Fat Meter®). The aim of the present study was to evaluate the consequences of this selective breeding on flesh quality of pan size (290g) diploid and triploid trout after three generations of selection. Instrumental evaluations of fillet color and pH measurement were performed at slaughter. Flesh color, pH, dry matter content and mechanical resistance were measured at 48h and 96h postmortem on raw and cooked flesh, respectively. A sensorial profile analysis was performed on cooked fillets. Fillets from the selected fatty muscle line (F) had a higher dry matter content and were more colorful for both raw and cooked fillets. Mechanical evaluation indicated a tendency of raw flesh from F fish to be less firm, but this was not confirmed after cooking, neither instrumentally or by sensory analysis. The sensory analysis revealed higher fat loss, higher intensity of flavor of cooked potato, higher exudation, higher moisture content and a more fatty film left on the tongue for flesh from F fish. Triploid fish had mechanically softer raw and cooked fillets, but the difference was not perceived by the sensorial panel. The sensorial evaluation also revealed a lower global intensity of odor, more exudation and a higher moisture content in the fillets from triploid fish. These differences in quality parameters among groups of fish were associated with larger white muscle fibers in F fish and in triploid fish. The data provide additional information about the relationship between muscle fat content, muscle cellularity and flesh quality.

Developing radio frequency technology for postharvest insect control in milled rice

Since methyl bromide fumigation has an adverse effect on human health and environment, it is urgently needed for developing a non-chemical method to replace chemical fumigation for disinfesting milled rice. The purpose of this research was to study possible applications of radio frequency (RF) energy for disinfesting milled rice without affecting product quality. A pilot-scale, 27.12 MHz, 6 kW RF system was used to study RF heating uniformity and develop a treatment protocol for achieving 100% insect mortality and finally evaluating quality attributes in RF treated milled rice during storage. The results showed that the heating time needed only 4.3 min to heat the 3.9 kg milled rice from 25 °C to 50 °C using RF energy, but 480 min for milled rice to reach 48 °C using hot air at 50 °C. After comparing three selected electrode gaps, an appropriate gap of 11 cm was obtained to achieve the heating rate of 5.8 °C/min for further heating uniformity tests. An RF treatment protocol was finally developed to combine 1.0 kW RF power with a forced hot air heating at 50 °C, movement of the conveyor with the speed of 12.4 m/h, two mixings, and holding at 50 °C hot air for 5 min, followed by forced room air cooling through single-layer (2 cm thick) samples. There were no significant differences in quality parameters (moisture, protein, fat, starch, hardness, and color) between RF treatments and untreated controls during storage (P > 0.05). Therefore, RF treatments may provide a practical, effective and environmentally friendly method for disinfesting milled rice.