Time-intensity analysis and acceptance test for traditional and light vanilla ice cream

The time-intensity profile and acceptance of traditional and light vanilla ice creams were determined in this study. Six samples of commercial Brazilian vanilla ice cream of three different brands, in traditional and light versions, were evaluated. The analysis of variance (ANOVA) and Tukey's means test were applied using SAS software and the Internal Preference Mapping was prepared using the XLStat software. The time-intensity analysis with 10 trained judges and three repetitions revealed a bitter taste in one traditional sample (TRA3) and a residual bitter taste in two light samples (LIG1 and LIG3), which were less accepted (p ≤ 0.05) by the consumers (averages acceptance 5.2 and 5.3, respectivelly). A residual sweet taste was identified in one light sample (LIG2), however this does not affect the acceptance of LIG2 and was preferred by the consumers. In the acceptance test (9-centimeter linear hedonic scale) with 117 consumers, flavor and texture were the attributes that influenced consumer acceptance (overall liking), and only brand 2 (TRA2 and LIG2) obtained good acceptance (averages 6.0 and 6.4, respectivelly) for both samples. Sample LIG2 was the preferred sample according to the Internal Preference Mapping. Sucralose and sorbitol showed to be the most appropriate sweetener system, in relation to aspartame and sodium cyclamate to replace sucrose in ice cream. The development of the time-intensity sensory profile and data from the acceptance tests obtained in the assessment of the traditional and light ice creams on the market could help the ice cream industry to adopt procedures to improve the quality and delineate new advertising strategies.     

The effect of soy protein concentrate addition on the physical, chemical, and sensory properties of strawberry flavored ice cream

The effect of soy protein concentrate (0, 1.5, 3, and 4.5%) on the physical, chemical, and sensory properties of strawberry flavored (0, 0.01 and 0.02%) ice cream samples was examined. All samples were analyzed for pH, titratable acidity, total solids, nitrogen, fat, ash, overrun, viscosity, meltdown, Hunter L-, a-, b- values, flavor, body and texture, and appearance. Substituting soy protein concentrate (SPC) in ice cream formula for non-fat dry milk (NFDM) positively influenced the nitrogen content, viscosity values, and melting and appearance properties of the ice cream samples while overrun values and flavor scores were negatively affected. SPC could be incorporated into the ice cream formula in the range of 1.5–3% devoid of significantly diminishing the physical, chemical, and sensory properties.     

Use of preference mapping to relate consumer preference to the sensory properties of a processed meat product (tinned cat food)

The technique of generalised Procrustes analysis was applied to laboratory panel assessments of appearance, texture and aroma properties of ten commercial variants of tinned cat food. These assessments were made using free-choice profiling and were compared with results obtained from a subsequent fixed-choice profiling experiment. A consumer trial was also performed in a local supermarket to collect preference scores for the cat food, and these scores were related to the laboratory assessments using preference mapping. These techniques can be used by product developers to ascertain the properties of meat products that are important in determining consumer preference.     

Photosensitized oxidation of cholesterol and altered oxysterol levels in sour cream: Effects of addition of cucumber pickles

The aim of this research was to examine whether sour cream (18% fat) is an exogenous source of oxysterols and whether it is possible to improve its antioxidative properties and to modulate cholesterol transformation by adding cucumber. To determine whether cucumber modifies the properties of sour cream, fresh cucumber or cucumber pickle (pH 3.3; 1.5% lactic acid) was added in an amount of 20%. The sour cream samples were then stored under light (450 lx, 590 cd, 120 lm) for 3 wk. After storage, the addition of the cucumber pickle increased total mesophilic aerobic bacteria from 7.5 to 9.3 log cfu/g and increased the l-lactic acid content from 6.1 to 9.7 g/L. The total conjugated linoleic acid content in sour cream with cucumber pickle also increased to 4.5 mg/g fat after storage, whereas the cholesterol content decreased to 3.44 g/kg fat. Importantly, with the addition of cucumber pickle, the total content of cholesterol oxidization products (COP) did not change after storage (1.7 mg/kg fat). By contrast, the total COP content in the control sour cream sample increased from 1.7 to 7.3 mg/kg fat over 3 wk of storage. The dominant COP before and after storage was 7β-hydroxycholesterol. Thus, despite exposure to light, adding cucumber pickle to sour cream modulates cholesterol transformation and effectively inhibits the formation of oxysterols.     

Physicochemical,bioactive, and sensory properties of persimmon-based ice cream: Technique for order preference by similarity to ideal solution to determine optimum concentration

In the present study, persimmon puree was incorporated into the ice cream mix at different concentrations (8, 16, 24, 32, and 40%) and some physicochemical (dry matter, ash, protein, pH, sugar, fat, mineral, color, and viscosity), textural (hardness, stickiness, and work of penetration), bioactive (antiradical activity and total phenolic content), and sensory properties of samples were investigated. The technique for order preference by similarity to ideal solution approach was used for the determination of optimum persimmon puree concentration based on the sensory and bioactive characteristics of final products. Increase in persimmon puree resulted in a decrease in the dry matter, ash, fat, protein contents, and viscosity of ice cream mix. Glucose, fructose, sucrose, and lactose were determined to be major sugars in the ice cream samples including persimmon and increase in persimmon puree concentration increased the fructose and glucose content. Better melting properties and textural characteristics were observed for the samples with the addition of persimmon. Magnesium, K, and Ca were determined to be major minerals in the samples and only K concentration increased with the increase in persimmon content. Bioactive properties of ice cream samples improved and, in general, acetone-water extracts showed higher bioactivity compared with ones obtained using methanol-water extracts. The technique for order preference by similarity to ideal solution approach showed that the most preferred sample was the ice cream containing 24% persimmon puree.     

Influence of hazelnut flour and skin addition on the physical, chemical and sensory properties of vanilla ice cream

The effect of hazelnut flour (1.5, 3 and 4.5%) and hazelnut kernel skin (1, 2 and 3%) on the physical, chemical and sensory properties of vanilla ice cream was examined. All samples were analysed for pH, titratable acidity, total solids, nitrogen, fat, ash, overrun, viscosity, meltdown, Hunter L‐, a‐ and b‐values, flavour, body and texture, and appearance. The samples with hazelnut flour exhibited higher pH, nitrogen, ash, viscosity, and L‐, flavour, body and texture, and appearance values than the samples with kernel skin. Samples with hazelnut flour and skin can be added to the ice cream mix to produce a non‐fat ice cream at 3% and 1% levels in combination with maltodextrin, respectively.     

Detection of aflatoxin M1 in milk,cheese and sour cream samples from Costa Rica using enzyme-assisted extraction and HPLC

Aflatoxins are toxic fungal metabolites, which can be found in feed. Aflatoxin M₁ (AFM₁) is excreted into milk when ruminants ingest aflatoxin B₁ contaminated feedstuffs. Due to its carcinogenic potential, contamination of milk and dairy products with AFM₁ may pose a risk for consumers. Hence, it is considered a public health concern. In this survey, the level of AFM₁ contamination of dairy products marketed in Costa Rica was determined by enzyme-assisted extraction, immunoaffinity clean-up and high-performance liquid chromatography coupled with a fluorescent detector (HPLC-FLD) in fluid milk (n = 70), fresh cheese (n = 70) and sour cream (n = 70) collected at local convenience stores and supermarkets. AFM₁ concentrations in milk and fresh cheese ranged from 19 to 629 ng/L and from 31 to 276 ng/L, with mean values of 136 ng/L and 74 ng/L, respectively, whereas none of the sour cream samples analysed tested positive for this aflatoxin. In 30 milk samples, and 10 cheese samples, AFM₁ concentrations surpassed threshold concentrations as established by the European Commission. Thus, sour cream and – to a lesser extent – cheese manufacturing seems to reduce the amount of AFM₁ present in milk, possibly due to fraction redistribution or microbiological degradation. The survey results reveal improper quality control procedures in the Costa Rican dairy industry. Therefore, a surveillance programme for dairy products in our country is recommended.     

Rheological properties of Colombian‐Caribbean‐coast sour cream from goat milk

The viscoelastic properties provide guidelines to help give meaning to the observations on food products, to relate them to the way in which their structures behave, and to predict or modify their properties. This study analyses the incidence of varying the initial fat content of goat milk on the rheological properties of prepared sour cream. Storage (G′) and loss modulus (G″), as well as complex viscosity (η*) and loss factor values (tan δ), were determined at different initial fat contents in goat milk (3.75%, 4.00% and 4.25%). The experimental data were adapted to Maxwell model. All the prepared samples of sour cream meet national and international microbiological standards, and the initial fat content of goat milk influenced the viscoelastic behaviour of sour cream. Structures with prevalent elastic (G′) behaviour were found, and the product that was prepared from goat milk with 4.00% fat content showed the highest elastic modules. This sour cream exhibited higher firmness and better adherence when compared to the samples that were obtained from 3.75% and 4.25% fat‐content milk. This sample also exhibited the lowest tangent of the phase angle. Sour cream that was prepared from milk with higher fat content (4.00% and 4.25%) exhibited a semi‐solid behaviour along the entire temperature range that was studied. On the contrary, rheological properties of sour cream from 3.75% fat‐content milk tend to increase at temperatures above 333.15 K. The viscoelastic behaviour of sour cream was successfully explained under Maxwell model, while data from dynamic viscosity (η′) were adapted to Arrhenius model. Microstructure analysis to the sample considered as the best (from milk with 4.00% of initial fat content) showed that the protein network presented a rough, open surface with aggregates and wide spaces.     

Relating consumer preferences to sensory attributes of instant coffee

The sensory profiles of 11 instant coffees including pure coffees (PC), coffee blends (CB) and a chicory instant drink (CID), commercially available in South Africa, were described and quantified. These were then related to consumer preferences (n=199) for the instant coffees using preference mapping. Based on consumer preferences, four consumer groups were identified, “pure coffee lovers” (23%), “coffee blend drinkers” (30%), “general coffee drinkers” (37%) and “not serious coffee drinkers” (10%). The “pure coffee lovers” prefer the more astringent, bitter, roasted, nutty and full-bodied flavour of the pure coffee samples. The less intense coffee flavour character, but higher sweetness and root flavour, typical of chicory blended instant coffee, were attributes that were preferred by the “coffee blend lovers”. The “general coffee drinkers” seem to consume coffee out of habit and are less concerned about the specific sensory properties of the coffee.     

Chemical properties and sensory quality of ice cream fortified with fish protein

BACKGROUND: Fish protein powder is a functional ingredient that can be used for enhancing the nutritional value of food products. In this study the effect of fortification with different levels of fish protein powder (FP) on chemical properties and sensory quality of Persian ice cream with 0, 30 and 50 g kg^?1 FP during storage at ? 18 °C for 4 months was investigated. RESULTS: Ice creams fortified with 50 and 30 g kg^?1 FP had significantly higher protein and solid‐non‐fat content than ice cream with 0% FP or 83, 69 and 51 g kg^?1 protein and 215, 204 and 181 g kg^?1 solid non‐fat, respectively. All products had the same levels of fat, lactose, acidity and pH. They had similar sensory quality after production except for colour, but sensory properties of fortified samples changed significantly after 2 months of storage. Colour faded, cohesiveness decreased, sandiness/coarseness increased, sweetness decreased and fish flavour and off‐odour increased. The control ice cream scored highest for additives odour and flavour. CONCLUSION: Development of ice cream fortified with fish protein powder could be an effective way to enhance nutritional and functional value of ice cream. But studies on storage stability, consumers' acceptance and attitudes are recommended if companies are planning to do so. Copyright © 2011 Society of Chemical Industry     

Effect of substituting whey cream for sweet cream on the textural and rheological properties of cream cheese

In the manufacture of cream cheese, sweet cream and milk are blended to prepare the cream cheese mix, although other ingredients such as condensed skim milk and skim milk powder may also be included. Whey cream (WC) is an underutilized fat source, which has smaller fat droplets and slightly different chemical composition than sweet cream. This study investigated the rheological and textural properties of cream cheeses manufactured by substituting sweet cream with various levels of WC. Three different cream cheese mixes were prepared: control mix (CC; 0% WC), cream cheese mixes containing 25% WC (25WC; i.e., 75% sweet cream), and cream cheese mixes with 75% WC (75WC; i.e., 25% sweet cream). The CC, 25WC, and 75WC mixes were then used to manufacture cream cheeses. We also studied the effect of WC on the initial step in cream cheese manufacture (i.e., the acid gelation process monitored using dynamic small amplitude rheology). Acid gels were also prepared with added denatured whey proteins or membrane proteins/phospholipids (PL) to evaluate how these components affected gel properties. The rheological, textural, and sensory properties of cream cheeses were also measured. The WC samples had significantly higher levels of PL and insoluble protein compared with sweet cream. An increase in the level of WC reduced the rate of acid gel development, similar to the effect of whey phospholipid concentrate added to mixes. In cream cheese, an increase in the level of added WC resulted in significantly lower storage modulus values at temperatures <20°C. Texture results, obtained from instrumental and sensory analyses, showed that high level of WC resulted in significantly lower firmness or hardness values and higher stickiness compared with cream cheeses made with 25WC or CC cream cheeses. The softer, less elastic gels or cheeses resulting from the use of high levels of WC are likely due to the presence of components such as PL and proteins from the native milk fat globule membrane. The use of low levels of WC in cream cheese did not alter the texture, whereas high levels of WC could be used if manufacturers want to produce more spreadable products.     

Relating consumer preferences to sensory and physicochemical properties of dry beans (Phaseolus vulgaris)

BACKGROUND: Dry beans (Phaseolus vulgaris) have a range of varieties, colours and sizes. Differences in physicochemical and sensory properties influence consumer choices for beans. This study related consumer preferences to sensory and physico‐chemical properties of selected bean varieties—Jenny, Kranskop, PAN 148, AC Calmont, PAN 150 and Mkuzi—grown in Mpumalanga (MP) and Free State (FS) in South Africa. RESULTS: Significant (P < 0.05) variety, location as well as location × variety interaction effects were found for both physico‐chemical and sensory properties of beans. Jenny‐FS, Mkuzi and PAN 148‐MP beans had relatively long cooking times (>60 min). Some beans (e.g. PAN 150 and Mkuzi beans) were described as bitter, soapy and metallic with a raw‐bean flavour whereas more preferred beans (e.g. Jenny‐MP, Kranskop‐MP) were sweet, soft and with a cooked‐bean flavour. CONCLUSION Apart from small seed size, sensory characteristics such as bitter taste, soapy and metallic mouthfeel and hard texture contributed to consumers' dislike of certain bean varieties. The sweet taste, cooked‐bean flavours, soft and mushy textures of the most accepted varieties seemed to be related to beans with good hydration capacities that facilitated softening during cooking. Copyright © 2007 Society of Chemical Industry     

Effect of fat content on the physical properties and consumer acceptability of vanilla ice cream

Ice cream is a complex food matrix that contains multiple physical phases. Removal of 1 ingredient may affect not only its physical properties but also multiple sensory characteristics that may or may not be important to consumers. Fat not only contributes to texture, mouth feel, and flavor, but also serves as a structural element. We evaluated the effect of replacing fat with maltodextrin (MD) on select physical properties of ice cream and on consumer acceptability. Vanilla ice creams were formulated to contain 6, 8, 10, 12, and 14% fat, and the difference was made up with 8, 6, 4, 2, and 0% maltodextrin, respectively, to balance the mix. Physical characterization included measurements of overrun, apparent viscosity, fat particle size, fat destabilization, hardness, and melting rate. A series of sensory tests were conducted to measure liking and the intensity of various attributes. Tests were also conducted after 19 weeks of storage at −18°C to assess changes in acceptance due to prolonged storage at unfavorable temperatures. Then, discrimination tests were performed to determine which differences in fat content were detectable by consumers. Mix viscosity decreased with increasing fat content and decreasing maltodextrin content. Fat particle size and fat destabilization significantly increased with increasing fat content. However, acceptability did not differ significantly across the samples for fresh or stored ice cream. Following storage, ice creams with 6, 12, and 14% fat did not differ in acceptability compared with fresh ice cream. However, the 8% fat, 6% MD and 10% fat, 4% MD ice creams showed a significant drop in acceptance after storage relative to fresh ice cream at the same fat content. Consumers were unable to detect a difference of 2 percentage points in fat level between 6 and 12% fat. They were able to detect a difference of 4 percentage points for ice creams with 6% versus 10%, but not for those with 8% versus 12% fat. Removing fat and replacing it with maltodextrin caused minimal changes in physical properties in ice cream and mix and did not change consumer acceptability for either fresh or stored ice cream.     

牛肉酸汤配方优化及其挥发性风味物质分析

目的 以辣椒和牛肉为原料,研究牛肉酸汤的最佳配方,并分析其挥发性风味物质.方法 通过单因素和正交试验,研究辣椒品种、牛肉预处理方法、姜蒜比例、葡萄糖乳糖比例对牛肉酸汤色差、总酸及感官评分的影响,得到牛肉酸汤最佳配方;利用顶空固相微萃取结合气相色谱-质谱联用(headspace solid-phase microextr...