脱脂糯小米米糠粉对面团流变学性质及馒头品质的影响

对比两种不同目数脱脂糯小米米糠粉（简称米糠粉）对面团流变学性质的影响;采用感官评价和质构分析相结合评价其对馒头品质的影响,确定其最适添加量。结果表明：两种粒度米糠粉在添加量为6%（质量分数,下同）以下时,对面团的粉质特性均有一定的改良作用。两种米糠粉的添加对面团的拉伸特性都有一定的恶化作用,但100～200 目米糠粉添加量为4%～6%和过400 目米糠粉添加量为6%～8%时,面团的拉伸特性恶化不明显。随着100～200 目米糠粉添加量的增加,馒头的白度值逐渐减小;添加量为4%～6%时馒头的硬度、弹性、咀嚼性和回复性都较好,且感官评价得分较高。过400 目米糠粉的添加对馒头的白度值影响相对较小,其添加量小于6%时馒头质构性质较好,且感官评价得分高于100～200 目米糠粉。综上所述,添加适量的米糠粉可以在一定程度上延缓馒头老化,100～200 目米糠粉的添加量应控制在4%～6%,过400 目米糠粉添加量应控制在6%～8%。     

Influence of particle size on the physicochemical properties and stickiness of dairy powders

The compositional and physicochemical properties of different whey permeate (WPP), demineralised whey (DWP) and skim milk powder (SMP) size fractions were investigated. Bulk composition of WPP and DWP was significantly (P < 0.05) influenced by powder particle size; smaller particles had higher protein and lower lactose contents. Microscopic observations showed that WPP and DWP contained both larger lactose crystals and smaller amorphous particles. Bulk composition of SMP did not vary with particle size. Surface composition of the smallest SMP fraction (<75 μm) showed significantly lower protein (−9%) and higher fat (+5%) coverage compared with non-fractionated powders. For all powders, smaller particles were more susceptible to sticking. Hygroscopicity of SMP was not affected by particle size; hygroscopicity of semi-crystalline powders was inversely related to particle size. This study provides insights into differences between size fractions of dairy powders, which can potentially impact the sticking/caking behaviour of fine particles during processing.     

EFFECTS OF DIFFERENT PEKMEZ (FRUIT MOLASSES) TYPES ON CHEMICAL, NUTRITIONAL CONTENT AND STORAGE STABILITY OF CAKE

Pekmez is a natural sugar source that is obtained by concentration of fruit juice up to 70–80% soluble dry matter concentration. In this research, different kinds of pekmezes (mulberry, apricot, elecampane, grape and watermelon) were used in cake formulations instead of crystal sugar. Some chemical and nutritional properties and storage stability of cakes were investigated. Total and reducing sugar content of pekmezes ranged from 36.78 to 65.38% and from 33.54 to 64.70%, respectively. While water activity and crust color values of cakes generally decreased with pekmez addition, ash and mineral contents increased. Hydroxymethylfurfural content of cakes was found between 2.03 and 15.78 mg/kg and the highest value was obtained with grape pekmez addition. Ca, Fe, K, P and Zn contents of pekmez-added cakes were 92.72–177.82 mg, 4.09–22.70 mg, 4501.99–7208.45 mg, 255.68–416.41 mg and 2.91–4.86 mg/100 g, respectively. After 21 days of storage, apricot- and watermelon-added cakes were found to be softer than others cakes and control.

PRACTICAL APPLICATIONS

Preparation of cake with pekmez addition improved the nutritional value and especially apricot and watermelon addition gave increased shelf life. A new nutritious and delicious product was improved with pekmez additions. Elecampane and grape pekmez-added cakes were found as alternative food sources of Fe for anemic persons.     

EFFECTS OF ALKALIZED COCOA POWDER AND SOY LECITHIN ON PHYSICAL CHARACTERISTICS OF CHOCOLATE BEVERAGE POWDERS

Chocolate beverage powders (CBPs) were produced from alkalized cocoa powder (ACP) at 10–30% and soy lecithin (SL) at 0–4%. Response surface methodology (RSM) was used to determine the optimum level of ACP and SL on sedimentation, wettability, bulk density, despersibility, moisture content and flavor acceptability. SL was effective on wettability, and it also showed an optimum level for sedimentation and bulk density, while ACP was found to be significant for all physical properties. For sensory evaluation, flavor was acceptable at 20% ACP level soy taste was detected by panelists in CBPs with high SL and low ACP contents. It was found that as the ACP content was increased the soy taste of CBPs decreased. For overall physical characteristics, the optimum levels of 20% of ACP and 2–4% of SL were selected.     

EFFECTS OF FUNCTIONAL DAIRY BASED PROTEINS ON NONFAT YOGURT QUALITY

Production of nonfat yogurt demands a careful control of quality parameters. It is common to use skim milk powder (SMP) to increase the total solid content of nonfat yogurt, but some functional dairy-based proteins, such as casein/caseinates and whey proteins, may improve the quality of nonfat yogurt.
The objectives of this study were to use whey protein isolate (WPI), sodium caseinate (NaCn) and yogurt texture improver (TI) in nonfat yogurt manufacture as an alternative for SMP, and to compare their potential influences on the physical, chemical and microbial properties of nonfat yogurts over a 12-day storage. All dry ingredients were added at 1% (w/v) concentration to yogurt milk. Yogurts differed from each other with different hardness values. Acetaldehyde contents of yogurts were in the range of 35–43 ppm. The acetaldehyde content of all yogurt types decreased during storage. The control yogurt had the most tyrosine content, and the WPI-fortified yogurt had the least. Using different dry dairy ingredients did not affect the numbers of starter cultures. In addition, no significant differences were observed among yogurt types regarding their mineral composition.

PRACTICAL APPLICATIONS

Functional dry dairy ingredients can be used to increase the total solid content of nonfat yogurt instead of using skim milk powder (SMP) or evaporation. Their high protein content, water-binding capacity, texture improvement properties and health benefits make these proteins suited for use in nonfat yogurts. This study compares the possible effects of using whey protein isolate (WPI), sodium caseinate (NaCn) and yogurt texture improver (TI) as an alternative for SMP on the physical, chemical and microbial properties of nonfat yogurts. It was found that substitution of SMP for WPI, NaCn and TI at the level of 1% affected the physical, chemical and microbial properties of nonfat yogurt.     

CHARACTERISTICS OF BEEF PATTIES USING OKARA POWDER

Four different levels of okara powder (2.5, 5.0, 7.5 and 10%) were used to obtain beef patties that were compared with controls with 10 and 20% fat. Okara addition affected some quality parameters of beef patties. Although the protein, fat, ash and carbohydrate contents of raw beef patties increased by the addition of okara, moisture content decreased. The same trends (except protein content) were observed after cooking. The addition of okara reduced the cholesterol content by about 2–28% for raw beef patties and 6–23% for cooked beef patties. However, addition of okara increased the energy values for raw and cooked beef patties with respect to control with 10% fat. The WHC, cook loss and shrinkage of beef patties improved by the addition of okara. The addition of okara increased the pH, L* and b* values of raw beef patties, but did not affect a* value. The effect of okara on the sensory properties was statistically significant and the overall acceptability scores of samples decreased after more than 7.5% okara powder addition . According to these results, addition of okara powder up to 7.5% can be recommended as an extender in beef patties production to improving certain quality parameters.

PRACTICAL APPLICATIONS

Okara is an abundant by-product of the soy and tofu industries and contains valuable components, including proteins, lipids, fibers and isoflavonoids. The addition of okara powder to beef patties reduces the cholesterol content and improves WHC, cook loss, shrinkage and sensory quality of the products. Okara powder can be added up to 7.5% for the production of patties.     

Why semicarbazide (SEM) is not an appropriate marker for the usage of nitrofurazone on agricultural animals

A comprehensive global database on semicarbazide (SEM) in foodstuffs and food ingredients is presented, with over 4000 data collected in foods such as seafood (crustaceans, fish powders), meat (beef, chicken powders), dairy products (e.g. raw milk, milk powders, whey, sweet buttermilk powder, caseinate, yoghurt, cheese), honey and other ingredients. The results provide evidence that the presence of SEM in certain dairy ingredients (whey, milk protein concentrates) is a by-product of chemical reactions taking place during the manufacturing process. Of the dairy ingredients tested (c. 2000 samples), 5.3% showed traces of SEM > 0.5 µg/kg. The highest incidence of SEM-positive samples in the dairy category were whey (powders, liquid) and milk protein concentrates (35% positive), with up to 13 µg/kg measured in a whey powder. Sweet buttermilk powder and caseinate followed, with 27% and 9.3% positives, respectively. SEM was not detected in raw milk, or in yoghurt or cheese. Of the crustacean products (shrimp and prawn powders) tested, 44% were positive for SEM, the highest value measured at 284 µg/kg. Fish powders revealed an unexpectedly high incidence of positive samples (25%); in this case, fraudulent addition of shellfish shells or carry-over during processing cannot be excluded. Overall, the data provide new insights into the occurrence of SEM (for dairy products and fish powders), substantially strengthening the arguments that SEM in certain food categories is not a conclusive marker of the use of the illegal antibiotic nitrofurazone.     

Thickness suitability of prebiotic dairy desserts: Relationship with rheological properties

In food product development it is important to know to what extent changes in formulation modifies the product, affecting its sensory properties and acceptability. Addition of polysaccharides like inulin can affect product structure in particular, modifying both rheological behaviour and perceived texture. The aim of this work was to assess to what extent rheological properties can explain the acceptability of thickness perceived by consumers in starch-based desserts. Low-fat dairy desserts were prepared varying the concentration of sucrose, flavor aroma and the fat replacer with prebiotic properties (inulin) but with fixed amounts of skimmed milk and starch. The rheological behavior was characterized and the level of sample thickness suitability was evaluated by a total of 100 consumers using a 5-point JAR scale (1 = too weak, 3 = just about right; 5 = too strong). Results indicated that flow and viscoelastic parameters varied among samples depending on inulin and sucrose concentration. According to sensory results, thickness suitability varied greatly between samples. The relationships between instrumental and sensory results are studied and discussed.     

Some Physical,Chemical, and Rheological Properties of Sweet Sorghum (Sorghum Bicolor (L) Moench) Pekmez (Molasses)

Some physical, chemical properties and the rheological behaviour of the sweet sorghum (Sorghum bicolor L Moench) pekmez (molasses) were determined. The rheological behaviour of the sweet sorghum pekmez (concentrated sorghum juice) with different soluble solid contents (75.1, 72.4, 66.5, and 59.4 °Brix) was determined in the temperature range of 10, 20, 30, 40, and 50°C using a rotational viscometer equipped with spindle 5 at the speed (share rate) of 5, 10, 20, 50, and 100 rpm. An empirical power law model was used to describe the rheological behavior of the sweet sorghum pekmez with correlation coefficients (R²) between 0.922 and 0.986. The sweet sorghum pekmez exhibited a pseudoplastic behavior. An Arrhenius equation was used to describe the effect of temperature on viscosity and E_a value of the sweet sorghum pekmez was calculated as 31 350 J/mol. Depending on the soluble solids contents, the activation energies for flow of diluted samples vary from 52.27 to 24.50 kJmol^?1. The effect of °Brix on viscosity can be described by the power-law equation. Experimental data were fitted to power law and exponential model in order to describe the effect of temperature and soluble dry matter content. Density and Electrical conductivity were measured 1.3915 g/cm³ and 13.53 mS/cm, respectively. The color as L, a and b value were measured 19.07, + 4.0, and + 2.18, respectively.     

Evaluation of sensory quality of instant foods fortified with omega-3 PUFA by addition of fish oil powder

The aim of this study was to evaluate the influence of fish oil powder fortification on sensory quality of selected instant foods. Two kinds of fish oil powders were tested. Upper levels of addition of fish oil powders to various instant foods, which not significantly influenced sensory quality, were established. In the storage test milk-rice kid cereal food with and without flavourings were fortified with fish oil powder and sensory evaluated. Decrease of sensory quality of samples stored in the air-permeable conditions was detected after 1 week (not flavoured) and 3 weeks (flavoured). However, vacuum-packed samples showed no changes in sensory quality. Presence of flavourings allowed higher levels of fish oil addition to instant foods due to masking of undesirable off-flavours. The authors concluded that it is possible to fortify instant foods with microencapsulated fish oil at limited levels, especially when spray-dried powders are used. One portion of fortified instant foods might provide up to 16% of the minimal recommended daily intake of long chain omega-3 PUFA.     

乳制品的流变学研究

乳制品的流变学特性与其质地、稳定性和工艺设计有重要关系。近年来，由于先进测试仪器的引入，食品科学家能例行地测定乳制品基础流变学性能。本文就乳制品与流变特性关系，流变学参数与感官质量评价间相关性作了叙述。     

In-situ lecithination of dairy powders in spray-drying for confectionery applications

Powders are essential ingredients of chocolate. In particular for milk chocolate milk and whey powders are important, together with sucrose, lactose and cocoa solids. During processing to maintain a good flow of the molten chocolate mass, particles with hydrophilic surfaces, such as dairy powders and sugars, are coated with a surface-active compound. Only lecithin and polyglycerol polyricinoleate (PGPR) (at a limited level) are allowed in chocolate, and as these are expensive as little as possible is added, whilst maintaining rheological properties. Conventionally, lecithin is added during conching, and through the intense kneading of the chocolate mass it is distributed throughout the mass. Usually about 0.5% is added, although the level depends upon the composition of the chocolate. Here we present a new approach to lecithination of spray-dried milk and lactose powders, which we call in-situ lecithination. It has been found that the surface of a spray-dried powder is dominated by any surface-active species, and in a competitive situation, the most rapidly adsorbing species dominates. This behaviour is utilised when lecithin is added to the spray-dryer feed, and through the competitive adsorption of surface-active agents during the drying process, it dominates the powder surface composition as measured by X-ray photoelectron spectroscopy (XPS). This is also seen in differences in sedimentation rate when the powders are mixed with cocoa butter to assess the rheological properties of the powder dispersions. The effect was large for lactose powders, but smaller for skim milk powder and whey powder.     

OPTIMIZATION OF GUAVA JUICE AND POWDER PRODUCTION

Enzyme treatment of guava puree was optimized for yield and clarity by first determining the most effective concentration, then varying both incubation time and temperature. Application of Pectinex Ultra SP-L® was optimal using 700 ppm enzyme for 1.5 h at 50C. Clarified guava juice was clearer (89.6%) when prepared using ultrafiltration (MW cut-off 40–60 kDa) rather than plate and frame filtration (82.8%); however, the latter was higher in both soluble solids and ascorbic acid. Clarified guava juice powders were made using freeze-drying, spray drying and tunnel drying. The freeze-dried product had superior quality; however, the spray-dried product was stable and may be more economical. Sensory panelists ranked the cloudy juice prepared from aseptic guava puree highest, and there were no significant differences between the juices from pasteurized, clear nectar, freeze-dried puree powder or juice powder.     

The effect of multiwall Kraft paper or plastic bags on physico-chemical changes in milk powder during storage at high temperature and humidity

Plastic bags have recently been introduced as an alternative to multiwall Kraft paper bags in packaging milk powder in 25-kg sizes as it is thought that plastic bags are more durable and would preserve the quality of milk powders during storage better than paper bags. However, there is little scientific information available on the performance of plastic bags for milk powder storage. The aim of this study was to compare the properties of skimmed milk powder (SMP) packaged in plastic or paper bags. Commercially produced and packaged SMP in 25-kg plastic or paper bags was stored at 37°C and 90% relative humidity. Samples were analysed at intervals (0, 45, 90 and 135 days) for moisture, water activity, lactic acid content, pH, insolubility index, bulk density, flowability, dispersibility and particle size. The magnitude of change in the majority of SMP properties measured during storage suggests that plastic bags are similar to paper bags in maintaining milk powder quality during storage.     

The Distribution of Fat in Dried Dairy Particles Determines Flavor Release and Flavor Stability

Dried dairy ingredients are utilized in various food and beverage applications for their nutritional, functional, and sensory properties. Dried dairy ingredients include milk powders of varying fat content and heat treatment and buttermilk powder, along with both milk and whey proteins of varying protein contents. The flavor of these ingredients is the most important characteristic that determines consumer acceptance of the ingredient applications. Lipid oxidation is the main mechanism for off‐flavor development in dried dairy ingredients. The effects of various unit operations on the flavor of dried dairy ingredients have been investigated. Recent research documented that increased surface free fat in spray dried WPC80 was associated with increased lipid oxidation and off‐flavors. Surface free fat in spray‐dried products is fat on the surface of the powder that is not emulsified. The most common emulsifiers present in dried dairy ingredients are proteins and phospholipids. Currently, only an association between surface free fat and lipid oxidation has been presented. The link between surface free fat in dried dairy ingredients and flavor and flavor stability has not been investigated. In this review, some hypotheses for the role of surface free fat on the flavor of dried dairy ingredients are presented along with proposed mechanisms.     

可微波鸡米花预混粉层配料的研究

采用单纯形格子法实验设计优化鸡米花层预混粉的配方，以获得鸡米花微波后表层松脆的口感，通过对鸡米花的脆性、感官指标以及色差的分析，确定预混粉最优的配方为：小麦淀粉21％，变性淀粉25％，蛋清粉2．5％，大豆蛋白4．5％，其他成分占47％。结果表明，采用优化后的预混粉层配方生产出的鸡米花，可以使微波后产品脆性得到显著的提高，而且产品的感官质量较好。     

Effects of partially replacing skimmed milk powder with dairy ingredients on rheology, sensory profiling, and microstructure of probiotic stirred-type yogurt during cold storage

This study aimed to evaluate the quality of stirred-type skim milk probiotic yogurt fortified by partially replacing skim milk powder (SMP) with whey protein concentrate (WPC) and sodium caseinate (Na-CN) during cold storage for 28 d compared with nonfortified yogurt. The rheological properties (as measured using dynamic oscillation) and sensory profiles of probiotic yogurts were greatly enhanced when SMP (i.e., 45%) was replaced with WPC and Na-CN. Higher values of mechanical parameters related to storage and loss modulus and consistent microstructure were found in the fortified yogurts. The acidification profile was not affected by supplementation of the solids in the milk base, and the viable counts of probiotic microbiota were high and satisfactory. These positive characteristics of probiotic yogurts were maintained until the end of the storage period. The microstructure of the fortified yogurt showed some differences compared with the nonfortified product, which were due to changes in chemical composition of the milk base in addition to the colloidal characteristics of the product.