Study of Commercial Wheat Flour Milling Process:Relation of Flour Yield,Ash and Protein Contents of Flour Mill and Characteristics of Wheat Blend

The profit margin in the flour milling industry is quite narrow,so high-quality raw materials and efficiency of milling operations are crucial for every company. Many flour mills,especially those which import wheat from other countries and have limited storage space for the different varieties or classes of wheat,can not afford to buy low quality wheat. Consequently,a mathematical model which can test the impact and interactions of raw materials,in technical point of view,would be a useful decision-making tool for the milling industry. A flour miller tests wheat for physical and chemical characteristics,cleanness and soundness. The miller also performs experimental milling,if available,to have some idea how the given wheat will behave during commercial milling. Based on these test results,the miller can only guess the commercial milling results such as flour yields and flour ash and protein contents. Thus,the objective of this study was to develop empirical equations to estimate commercial milling results,using the physical,chemical and experimental milling data of the given wheat blend and also,additionally,flour ash and protein specifications of the end-user. This was done by using the actual commercial milling procedures and their wheat physical,chemical,experimental milling data,and other vital data. Data were collected from a commercial mill located in East Asia that had four production lines and used wheat blend combinations from five different wheat classes,i.e. Hard Red Winter (HRW),Dark Northern Spring (DNS),Soft White (SW),Australian Soft (AS),and Australian Standard White (ASW) wheat to produce over 40 different products. The wheat physical and chemical characteristics included test weight,thousand kernel weight,ash and protein contents. The experimental milling data were straight-grade and patent flour yields,along with patent flour ash and protein contents from a Buhler experimental mill. The commercial milling results included the flour yields of patent,first clear,and second clear flours,as well as the ash and protein contents of commercial patent flours. Using multiple linear regression procedures,we have developed empirical equations to be able to estimate the commercial patent flour yields with R2 values above 0.90 for all four production lines,and commercial first clear flour yields with R2 values ranging 0.76 to 0.98,and the commercial patent flour protein contents with R2 values of 0.89 to 0.92. However,the yields of commercial second clear flours and the commercial patent flour ash contents were not able to be estimated with high coefficients of determination (R2 values). We recommend that the empirical equations for estimating commercial milling parameters should be derived using data from each individual flour milling company,for each production line of a given mill,and furthermore,tailored to specific products at a given ash and/or protein contents desired by end-users.

Effects of Milling Methods on Rice Flour Properties and Rice Product Quality:A Review

High-quality rice flour is the foundation for the production of various rice-based products.Milling is an essential step in obtaining rice flour,during which significant changes occur in the physicochemical and quality characteristics of the flour.Although rice flour obtained through mainstream wet milling methods exhibits superior quality,low production efficiency and wastewater discharge limit the development of the industry.Dry milling,on the other hand,conserves water resources,but adversely affects flour performance due to excessive heat generation.As an emerging powder-making technique,semi-dry milling offers a promising solution by enhancing flour quality and reducing environmental impact.This is achieved by minimizing soaking time through hot air treatment while reducing mechanical energy consumption to reach saturated water absorption levels.However,continuous production remains a challenge.This comprehensive review summarizes the effects of various milling technologies on rice flour properties and product qualities.It also discusses key control indicators and technical considerations for rice flour processing equipment and processes.

Study and Formulation of Composite Flours Based on Gluten Flour and Local Cereal Flours: Fonio, Millet and Sorghum

This study makes it possible to establish baking flours of nutritional quality and technologically acceptable following the increase in their rheological parameters due to the insertion of gluten flour. The composite flours were obtained using the Philips mixer type (model HR2811). The nutritional qualities of the formulated flours were determined by the Kjeldahl, AOAC 985-29, UV-VIS spectrophotometry (DR 5000;HACH and LANGE, France) and Soxhlet gravimetric methods. The compounds obtained are respectively: Protein, carbohydrate, lipid, micronutrient and vitamin contents. Monitoring the analysis of functional properties (water and oil absorption capacity) as well as baking value.

Preparation of lactic acid bacteria compound starter cultures based on pasting properties and its improvement of glutinous rice flour and dough

The effects of 5 lactic acid bacteria(LAB)fermentation on the pasting properties of glutinous rice flour were compared,and suitable fermentation strains were selected based on the changes of viscosity,setback value,and breakdown value to prepare LAB compound starter cultures.The results revealed that Latilactobacillus sakei HSD004 and Lacticaseibacillus rhamnosus HSD005 had apparent advantages in increasing the viscosity and reducing the setback and breakdown values of glutinous rice flour.In particular,the compound starter created using the two abovementioned LAB in the ratio of 3:1 had better performance than that using a single LAB in improving the pasting properties and increasing the water and oil absorption capacity of glutinous rice flour.Moreover,the gelatinization enthalpy of the fermented samples increased significantly.For frozen glutinous rice dough stored for 28 days,the viscoelasticity of frozen dough prepared by compound starter was better than that of control dough,and the freezable water content was lower than that of control dough.These results indicate that compound LAB fermentation is a promising technology in the glutinous rice-based food processing industry,which has significance for its application.

Nutritional and Sanitary Quality of Infant Flours Produced in Ouagadougou, Burkina Faso

The quality of infant flours used during the weaning age is of great importance in that it conditions the nutritional health of infants and young children. This study aimed to assess the nutritional and sanitary quality of infant flours produced in the city of Ouagadougou. This was a cross-sectional study including 11 out of 25 infant flour production units that gave their consent to partake in the study. In total, 25 infant flour samples have been collected from July to September 2021. The physicochemical and microbiological parameters were determined according to standard methods. The ANOVA analysis of variance showed significant differences between the means of the physico-chemical and the means of the microbiological parameters respectively. The results showed that 60% of proteins and 80% of lipid and total carbohydrate contents were below the authorised limits. The energy values were below the authorised limit in 88% of the cases. All instant infant flours had microbiological loads compliant with Burkinabè standards. As for infant flour to be cooked, 63.64% and 81.82% had satisfactory numbers of total coliforms and faecal coliforms respectively. Staphylococcus aureus and Escherichia coli were detected in these samples with 86.36% of infant formulae having results below the recommended limit. These results show that the infant flours produced in Ouagadougou were somehow of acceptable quality. However, there is a need to improve the formulae for macronutrient contents, energy values and sanitary quality to comply with the recommendations.

Formulation of Infant Flours Based on Fonio Enriched with Bambara Groundnut Anacardium (Cashew) and African Locust Bean Fruit Pulp

Infant malnutrition is a significant issue in Côte d’Ivoire, and this study aims to address it by formulating infant flours using local ingredients. Fermentation, germination, and malting methods were used to enhance the quality of six formulated flours, all based on Fonio and supplemented with Bambara groundnut, African locust bean fruit pulp, and cashew kernels. Results showed that Fonio had the highest carbohydrate content, while Bambara groundnut and Cashew kernels were rich in protein and lipid content. African locust bean fruit pulp was rich in fiber and Vitamin C, with a high β-carotene value. The cashew kernel had the highest energy value. Regarding mineral composition, African locust bean fruit pulp had the highest potassium content, while Bambara groundnut and African locust bean fruit pulp were rich in sodium. Cashew kernel and Fonio had higher iron and calcium content. Bambara groundnut had a higher zinc content, while cashew kernel had a higher magnesium content. The formulated flours made from fermented Fonio grains and enriched with Bambara groundnut, African locust bean fruit pulp, and cashew kernel had varying protein, fiber, carbohydrate, ash, and fat contents. The flour formulated with sprouted Fonio and enriched with the same ingredients had higher protein content and energy value than the other fermented seed-based flours. The mixed flours produced with fermented seeds and the flour produced from sprouted seeds met international standards. Overall, these findings offer valuable insights into the nutritional composition of the formulated flours and their potential to combat infant malnutrition in Côte d’Ivoire.

Physicochemical Characterisation of Flours from Local Cereals and Powder from Cassava (Manihot esculenta Crantz) Leaves Varieties Cultivated in the Northern-Cameroon in Order to Supplement Infant Flours

The aim of the present study was to investigate on the inventory and determination of the nutritional value of cereals flour and cassava leaves powder in order to analyse their use in the production of infant flour. In this paper, a A survey to identify the cereals used in the preparation of infant porridge in the Northern Cameroon was done by using 447 mothers having children between 06 and 59 months from areas (Gbakoungue, Sassa-Mbersi, Sanguere-Ngal and Kotkong-Wouldata) with high rate on malnourished children. Flour was prepared from the most preponderant cereals and Cassava leaves powder from varieties identified by the Regional Centre of Agricultural Research (CRRA) of Wakwa and local population. Flour and powder samples obtained were subjected to chemical composition analysis. Parameters analysed were crude proteins, total carbohydrates, ash, total fats, total phenols, total tannins, total carotenoids, vitamin C or cyanide. Also Iron, calcium and zinc were determined. The results revealed that white maize (62%) was the main cereal used in the preparation of infant porridge followed respectively by red sorghum, white rice and muskwari. Ten cassava varieties were identified: three (03) by CRRA (TME, 96/1/14 and IRAD 4115) and seven (south, gambada, sweet, Benin, six months, M. glaziovii and grouna) by local population. Amongst cereals flour, those from white maize indicated high protein (10.09%), carbohydrates (84.46%) and total fat (7.46%) contents. The powder from 96/14/14 cassava variety showed high amount of iron (11.98 mg/100g), calcium (751.02 g/100g) and low cyanide content (1.21 ppm) amongst all the cassava leaves powder samples. The supplementation of white maize flour by cassava leaves powder from 96/14/14 variety could therefore be recommended for the preparation of infant flours.

Design and Production of Infant Flours Based on Pumpkin Pulp Enriched with Cakes Extracted from Its Seeds

The inclusion of composite flours in infant food at weaning time should be a priority for mothers. The aim of this project is to formulate infant flour based on pulp flour enriched with oilcake from these grains after extraction of the oil. To do this, the elements were combined to obtain a regulatory formulation. Micro- and macronutrients, minerals, vitamins and tasting of the prepared porridge were determined. The results obtained were satisfactory. The moisture content of the fruit pulp was determined using oven-drying techniques: 92.2%, carbohydrates 6.00%, lipids 0.3%, ash 0.80%, proteins 1.10%, calcium 19.8%, phosphorus 42.6% and iron 0.4%. Furthermore, the carbohydrate content of flours composed of 5% insertion is 62.9 g to 48.8 g per 100 g, and the protein content of compound flours with 5% insertion is 15.9 g to 28.25 g per 100 g. On the other hand, the vitamin C and E contents of fresh pulp and oilcake are 25 mg, 13 mg and 21 mg respectively. However, only copper and β-carotene from 5% to 30% insertion remain invariant to the different insertion rates, with a value of 25 mg for copper and 0 µg for β-carotene. In addition, a variation in the degree of swelling of weaning flours compared with the standard from 3.95% at 5% insertion to 3.58 at 30% insertion was observed. The solubility of flours increases on the one hand with increases in the degree of insertion of the cakes. Flour formulated so many toward basicity. But the presence of traces of oil containing fatty acids can reduce this basicity. This study may be an alternative of industrial flours in infant nutrition.

Correlation between Milling Flour Quality of Xinjiang Spring Wheat and Processing Quality of Xinjiang Hand-stretched Noodle

In the research,36 spring wheat cultivars from Xinjiang were used to investigate flour yield,ash content,color,granularity,flour quality,paste quality and gelatinization property and to evaluate processing quality and characters of stretched noodle,in order to explore relationship of milling flour quality with quality property of Xinjiang spring wheat and with processing quality of Xinjiang hand-stretched noodle,which provides theoretical references for improvement of Xinjiang spring wheat cultivars,breeding of specific cultivars（for Xinjiang stretched noodles）,and advancement of stretched noodles.The results indicated that flour color is dominant among flour quality properties of Xinjiang spring wheat,which is of significant correlation with processing quality of stretched noodles.Therefore,in quality improvement of Xinjiang stretched noodles,flour yield of Xinjiang wheat should be enhanced and ash content and damaged starch should be reduced in order to improve quality of flour and stretched noodles from Xinjiang spring wheat.The indices of milling flours for Xinjiang stretched noodles are as follows：flour yield ≥60.77%,ash content ≤ 0.45%,damaged starch≤3.77%,granularity ≤108.14%,brightness（L^＊）≥ 90.86,redness（a^＊）≥-0.82,and yellowness（b^＊） ≤9.00.

Phytic Acid Contents of Wheat Flours from Different Mill Streams

The phytic acid contents of eight fractions of wheat flours from different mill streams and those in wheat brans, which were separated by different sieves into various sizes, were determined and analyzed. A rapid method for phytic acid assay by adding thioglycolic acid （mercapto acetic acid） with 2,2-bipyridine was used, with an acidic iron-Ⅲ-solution of known iron content. The amount ofphytate was indicated by the decrease in iron in the supernatant. Significant differences were observed in phytic acid content among different milling streams and different cultivars （P〈0.05）. On an average, coarse bran had the highest phytic acid content （53.85 mg g^-1）, and the shorts had 28.48 mg g^-1. The B5 break flour had a higher phytic acid content （4.8 mg g^-1） than the B7 （2.75 mg g^-1） and B8 （2.03 mg g^-1） reduction flours. Lower values were found in the B3, B6 and B7 flours （1.07, 0.79, and 0.76 mg g^-1, respectively）. The phytic acid contents of bran decreased with smaller bran sizes, ranging from 54 to 5.09 mg g^-1.

Effects of Dry-Milling and Wet-Milling on Chemical, Physical and Gelatinization Properties of Rice Flour

Rice flour from nine varieties, subjected to dry- and wet-milling processes, was determined for its physical and chemical properties. The results revealed that milling method had an effect on properties of flour. Wet-milling process resulted in flour with significantly lower protein and ash contents and higher carbohydrate content. Wet-milled flour also tended to have lower lipid content and higher amylose content. In addition, wet-milled rice flour contained granules with smaller average size compared to dry-milled samples. Swelling power at 90℃ of wet-milled samples was higher while solubility was significantly lower than those of dry-milled flour. Dry milling process caused the destruction of the crystalline structure and yielded flour with lower crystallinity compared to wet-milling process, which resulted in significantly lower gelatinization enthalpy.

Production of microbial medium from defatted brebra(Milletia ferruginea)seed flour to substitute commercial peptone agar

Objective:To investigate and optimize microbial media that substitute peptone agar using brebra seed defatted flour.Methods:Defatted process.inoculums preparation,evaluation of bacterial growth,preparation of cooked and hydrolyzed media and growth turbidity of tested bacteria were determined.Results:Two percent defatted flour was found to be suitable concentration for the growth of pathogenic bacteria:Escherichia coli(ATCC 25922)(E,coli),Pseudomonas aeruginosa(ATCC27853),Salmonella(NCTC 8385)and Shigella flexneri(ATCC 12022)(S.flexneri),while 3%defatted flour was suitable for Staphylococcus aureus(ATCC 25923)(S.aureus).E.coli(93±1)and S.flexneri(524±1)colony count were significantly(P≤0.05)greater in defatted flour without supplement than in supplemented medium.E.coli[(3.72×10~9±2)CFU/mL],S.aureus[(7.4×10~9±2)CFU/mL],S.flexneri[(4.03×10~9±2)CFU/mL]and Salmonella[(2.37×10~9±1)CFU/mL]in non-hydrolyzed sample were statistically(P≤0.05)greater than hydrolyzed one and commercial peptone agar.Colony count of Salmonella[(4.55≤10~9±3)CFU/mL],S.flexneri[(5.40≤10~9±3)CFU/mL]and Lyesria moncytogenes(ATCC 19116)[(5.4×10~9±3)CFU/mL]on raw defatted flour agar was significantly(P≤0.05)greater than cooked defatted flour and commercial peptone agar.Biomass of E.coli,S.aureus.Salmonella and Enterococcus faecalis in non-hydrolyzed defatted flour is highly increased over hydrolyzed defatted flour and commercial peptone broth.Conclusions:The defatted flour agar was found to be better microbial media or comparable with peptone agar.The substances in it can serve as sources of carbon,nitrogen,vitamins and minerals that are essential to support the growth of microorganisms without any supplements.Currently,all supplements of peptone agar are very expensive in the market.

Effect of Glutinous Rice Flour on Mechanical Properties and Microstructure of Cement-based Materials

The mechanism of glutinous rice flour,a kind of natural admixture,on the hydration process,setting time,and microstructure of the Portland cement was investigated.The experimental results show that the glutinous rice flour has an obvious setting retarding effect on cement pastes.The optimal dosage of the glutinous rice flour is 3wt%.In this case,the initial and final setting time of the paste are delayed by 140 and185 min,respectively.The flexural and compressive strengths of the hardened paste are increased by 0.35%and 0.07%after 56 d of curing.The glutinous rice flour hinders the mineral dissolution process and decreases the concentration of calcium ion at the initial stage of hydration due to the complexation effect,thereby hindering the nucleation and growth of CH and C-S-H phases and prolonging the hydration process.However,C-S-H phases combine with the glutinous rice flour to contribute the bonding effect together,which compacts the microstructure of hardened cement pastes at the later hydration stage of cement pastes.Thus,in-depth investigation on the utilization of glutinous rice flour as the admixture for the Portland cement is expected to be meaningful for the control of hydration exothermic rate and setting time.

Functional properties,antioxidant activity and in-vitro digestibility characteristics of brown and polished rice flours of Indian temperate region

The present investigation was aimed to study functional properties,antioxidant activity and in-vitro digestibility characteristics of brown and polished flours obtained from four rice cultivars(SR-4,K-39,Mushq Budij and Zhag)of Kashmir.Brown rice flours had higher total dietary fibre(3.08%-3.68%),oil absorption(116.0%-139.0%),emulsion capacity(4.78%-9.52%),emulsion stability(87.46%-99.93%)and resistant starch content(6.80%-9.00%)than polished flours.However,polished flours presented greater water absorption(102.0%-122.0%),foaming capacity(8.00%-13.63%),apparent amylose(19.16%-22.62%),peak(2260.0-2408.0 cP),trough(1372.0-1589.0 cP)and breakdown(714.0-978.0 cP)viscosities than their brown counterparts.Brown rice flours depicted highest total phenolic content(4.40-6.40 mg GAE/g)and inhibition of lipid peroxidation(19.50%-33.20%).However,equilibrium starch hydrolysis percentage(C∞)and predicted glycemic index of brown rice flours were lower than their polished counterparts.Among rice cultivars,brown Zhag flour had the highest total dietary fibre(3.68%),emulsion capacity(9.52%),emulsion stability(99.93%),resistant starch(9.00%),DPPH radical scavenging activity(85.45%)and inhibition of lipid peroxidation(33.20%),respectively.Emulsion capacity and emulsion stability were positively correlated with protein content of rice flours.However,peak,trough,breakdown and setback viscosities were negatively correlated with protein and fat contents of rice flour.The present investigation will be helpful in identifying nutritive role of rice flours from studied cultivars in human diet.

Effect of Fermentation on Nutrient and Anti-nutrient Composition of Millet （Pennisetum glaucum） and Soyabean （Glycine max） Blend Flours

This research was carried out to study the effect of fermentation on the chemical composition, anti-nutrient content, PH, titratable acidity, and microbiological changes of millet and soyabean blend. Millet and soyabean composite flours were mixed in gram of six combinations as follows millet and soyabean （A） = 100：0, millet and soyabean （B） = 90：10, millet and soyabean （C） = 80：20, millet and soyabean （D） = 70：30, millet and soyabean （E） = 60：40, millet and soyabean （F） = 50：50 and subjected to natural fermentation for 72 h. The following bacteria isolates were obtained from the fermentation; Lacobacillus fermentum, L. acidophilus, L. bulgaricus, L. plantarum, L. dextranicum, L. rhamnosus, L. delbrueckii, L. leichemanii, L. divergens, L. reuteri, L. jenseni, L. casei, L. salivarius, L. cellubiosus, Leuconostoc mesenteroide and Pediococcus acidilactis, of which L. plantarum was the most dominant the throughout the period of fermentation. There was decrease in pH with increase in TTA in all the samples. The result of the proximate analysis revealed a marginal increase in crude protein content of each sample （from 44.41 to 63.14, from 11.02 to 24.02, from 16.64 to 23.10, from 20.83 to 26.93, from 25.43 to 30.12, 39.12 to 35.86 and from 40.66 to 54.24%） There was increase in ash content and decrease in carbohydrate, fibre and fat contents of the fermented samples. Results from this research also show significant reduction in anti-nutritional content which are hydrogen cyanide, oxalate and phytate. Fermentation has modified the microbial and nutritional quality of the millet and soyabean blend and this has greatly improved the nutrient content of the blend.

Assessment of the Aflatoxin Content of Maize Flours Produced in the Commune of Ouagadougou, Burkina Faso

Aflatoxins are toxic metabolites present in various foods, especially when production and conservation do not respect good hygiene practices (GHP). In Ouagadougou, maize flour is produced and sold in different structures by actors who do not always respect GHP. Thus, it is necessary to regularly control the quality of these flours. So, this is carried out with the aim to assess the aflatoxin content of maize flours produced in the municipality of Ouagadougou. For this, twenty-eight (28) samples were collected from households, markets and supermarkets in the city of Ouagadougou. Thus, LC/MS/MS analysis was used to assess the aflatoxin content of the samples. The results obtained reveal the presence of total aflatoxins (AFT) in 78.57% of samples analyzed with levels ranging from 0.89 to 64.25 μg/kg. The prevalence of different types of aflatoxins were 57.14% for aflatoxin B1 (AFB1), 46.43% for aflatoxin B2 (AFB2), 42.86% for aflatoxin G1 (AFG1) and 4.6% for aflatoxin G2 (AFG2). The results also show that 80% and 60% of market samples, 70% and 30% of household samples and 37.5% and 25% of supermarket samples do not comply with European Commission standards for AFT and AFB1 respectively. For all the samples, 60.71% and 42.86% of the samples are compliant according to the limits established by the European Commission (EC) respectively for AFB1 and AFT. Regarding the results obtained, producers and processors must be supervised and trained in GHP for the production of better-quality flours.

Occupational exposure to flour dust among bakery workers:prevalence,potential hazards and promising interventions

Occupational exposure to flour dust within bakery environments presents significant health hazards to bakery personnel.Flour dust,generated as a byproduct during baking,becomes airborne during the baking process,thus constituting a respiratory threat.Adverse health consequences include respiratory diseases,skin irritation,allergic reactions,and potential long-term health impacts.Data indicates that a broad segment of bakery workers encounters exposure to flour dust,with specific subgroups,such as bakers and dough mixers,being particularly susceptible.Contributing factors to this exposure encompass insufficient ventilation and a lack of awareness.It is vital to assess exposure levels through air quality monitoring and health surveillance.Efficient interventions encompass engineering solutions(e.g.,ventilation systems,dust extraction),administrative measures(including training and the use of personal protective equipment),and the implementation of occupational health and safety programs.Collaborative efforts with healthcare professionals and regulatory authorities are paramount for achieving success.Case studies underscore the effectiveness of such interventions,resulting in improved worker health,thus underscoring the advantages of protective measures.Challenges in this endeavor include industry resistance to change,financial considerations,and issues related to compliance.Future recommendations entail further research,policy enhancements,and the involvement of industry stakeholders and labor unions in advocating for worker safety.

Availability, Accessibility and Contribution of Infant Flours to the Diet of Children Aged 6-59 Months in Benin

This study assesses the nutritional composition as well as the availability and affordability of infant flour found on the market and in the households of Benin. To do that assessment, a two-step cross-sectional survey based on food ethnography methods was used. A total of 61 marketplaces were visited in seven towns and rural districts as part of the availability and affordability survey, while 400 children (aged 6 to 59 months) were surveyed to track the uses of infant flours at the household level. The results obtained reveal that pre-manufactured infant flour is sold more in urban areas (Cotonou, Porto-Novo and Parakou) than in rural ones. The average infant flours price did not vary (p = 0.985) in any given year (regardless of abundance or lean periods) nor does it vary (p = 0.133) from one point of sale to another (drugstore or supermarkets). However, the average price is found to be expensive considering the purchasing power of the households surveyed. On the other hand, the amount of ingredients used in the production of the flour types found on the market complies with the recommendations of the Codex Alimentarius, unlike the homemade ones. Pre-manufactured infant flour is found to be outside of the economic reach of most households (92%) who rely heavily on the homemade ones to feed their children. In light of the above, public authorities should help improve geographic access and pricing affordability to quality infant flour for low-income households in urban and remote areas. Moreover, awareness should be raised among mothers relative to the importance of complementary feeding through education on good nutrition practices.

小麦粉加工车间硫酰氟整体熏蒸杀虫效果评估

研究了我国华南地区某小麦粉加工车间B区、C区,长为108 m,宽为25 m,高为35.2 m,总体积为95040 m^(3),有效熏蒸体积为53842 m^(3)的空间,采用硫酰氟剂量为40 g/m^(3)、密闭时间为48 h的整体性结构熏蒸。在不补充硫酰氟熏蒸剂的条件下,熏蒸过程浓度随时间变化的规律,建立了熏蒸剂的日损失率L d和浓度半数衰减时间HLT,分析了各楼层硫酰氟浓度变化规律和熏蒸剂泄漏程度,评估了杀虫效果。熏蒸剂的日损失率符合模型:L_(d)=100×(1-e^(-b))(e为自然常数;b为衰减常数),浓度半数衰减时间HLT符合模型:HLT=ln^(2)/b。熏蒸剂日损失率的变化随着衰减常数的增大而增大,浓度半数衰减时间HLT的变化随着衰减常数的增大而减小。单次熏蒸时衰减常数为固定值,熏蒸剂日损失率、浓度半数衰减时间HLT为恒定变化。经模型评估,6楼~8楼的日损失率L_(d)和半数衰减时间介于56.7%~71.3%和0.56~0.83 d。3、4楼区域损失率L_(d)和半数衰减时间介于85.0%~92.6%和0.27~0.37 d;除8楼硫酰氟熏蒸剂浓度半数衰减时间HLT超过15 h,其余楼层均未超过15 h。熏蒸后22 d,取样检测发现小麦粉加工车间设备和管道中均发现赤拟谷盗幼虫活虫。采用硫酰氟进行建筑物结构40 g/m^(3)剂量、密闭时间48 h方式熏蒸,可将车间空间区域害虫各虫态以及管道和设备中成虫杀死,存在于设备和管道内的卵可能存活且发育成新幼虫或蛹。

不同制粉方式对黑小麦全麦粉及饼干品质影响

该文以整粒粉碎法与回添法制得黑小麦全麦粉,研究不同制粉方式对全麦粉营养成分、粉质特性、抗氧化性成分与抗氧化能力的影响,探讨2种不同工艺全麦粉对饼干质构、抗氧化能力、货架期的影响。结果表明,2种制粉方式对全麦粉蛋白质、淀粉、脂肪含量基本无影响。回添全麦粉损伤淀粉含量少,湿面筋含量高;粉质弱化度小,面团稳定时间、粉质质量指数大;抗氧化成分与抗氧化能力下降。回添全麦粉制得的饼干硬度与脆性较低,口感更佳;饼干抗氧化能力下降,不会导致货架期显著下降。