Investigation of the possible use of probiotics in ice cream manufacture

This study attempted to investigate the possibility of using some types of probiotic bacteria in the production of ice cream and was aimed at making a contribution to the manufacture of new functional foods. For this purpose, different cream levels (5% and 10%) and different strains of probiotic bacteria ( Lactobacillus acidophilus , Bifidobacterium bifidum and both) were used in ice cream production to determine their effects on the quality of the ice creams in each group. During storage of 1, 15, 30, 45, 60, 75 and 90 days, L. acidophilus , B. bifidum counts and sensory analyses were performed. The results obtained at the end of storage demonstrated that the counts of L. acidophilus and B. bifidum continued to decrease during the storage but all types of ice cream sample seemed to preserve their probiotic property even after 90 days. Higher counts of probiotic bacteria were observed in the samples with L. acidophilus , B. bifidum , and L. acidophilus and B. bifidum in double-cultured samples respectively. In general, it appeared that the ice cream samples with 5% cream content were found to be more delectable. All ice cream samples have shown good results in preserving their probiotical properties for more than 3 months. Although sensory scores of probiotic ice cream samples reduced during this time, they rated as 'tasty' throughout the storage.     

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     

Use of gamma radiation in sheep butter manufacturing process for shelf-life extension

Gamma-irradiated sheep cream (1 kGy) was used to produce butter that was analysed during refrigerated storage up to 90 days in shelf-life extension studies including sensory, microbiological and water content assessments. The water content of the sheep butter made with irradiated fermented cream was 10% higher than that of control butter. A slower increase in bacterial load during storage was detected for the butter manufactured with irradiated fermented sheep cream compared with control butter; however, fungi increased at similar rates in both cream-irradiated and control butters during storage. The sensory evaluation suggested, in general, the acceptance of the irradiated samples by the panellists. The microbiocidal potential of gamma radiation of fermented sheep cream was highlighted, but was not reflected in extension of shelf-life of the butter produced. The traditional manufacturing process itself was found to be a major vehicle for microbial contamination of this dairy product, preventing its shelf-life extension.     

葵花籽油基油凝胶在面包及冰淇淋产品中的应用研究

以葵花籽油为基料油,食品级植物蜡(米糠蜡、蜂蜡、棕榈蜡)作为凝胶剂构建油凝胶,分别以黄油、起酥油、葵花籽油作对照烘焙面包,以黄油、淡奶油作对照制备冰淇淋,对比分析不同油脂制作的面包和冰淇淋的感官及物性。结果表明:与对照组面包相比,油凝胶面包在各项指标上均无太大劣势,同时,油凝胶面包烘焙损失率比用传统黄油和起酥油烘焙面包小,且饱和脂肪酸含量降低;在抗融化性能方面,蜂蜡油凝胶冰淇淋和棕榈蜡油凝胶冰淇淋的抗融化性能好于黄油冰淇淋,但油凝胶冰淇淋膨胀率较低,不利于冰淇淋形成疏松绵软结构,且有少许蜡感,还需进一步改进。     

Oxidation and textural characteristics of butter and ice cream with modified fatty acid profiles

The primary objective of this study was to evaluate oxidation and firmness of butter and ice cream made with modified milkfat containing enhanced amounts of linoleic acid or oleic acid. The influence of the fatty acid profile of the HO milkfat relating to product properties as compared with the influence the fatty acid profile of the HL milkfat was the main focus of the research. Altering the degree of unsaturation in milkfat may affect melting characteristics and oxidation rates, leading to quality issues in dairy products. Three milkfat compositions (high-oleic, high-linoleic, and control) were obtained by modifying the diets of Holstein cows. Ice cream and butter were processed from milkfat obtained from cows in each dietary group. Butter and ice cream samples were analyzed to determine fatty acid profile and firmness. High-oleic milkfat resulted in a softer butter. Solid fat index of high-oleic and high-linoleic milkfat was lower than the control. Control ice cream mix had higher viscosity compared with high-oleic and high-linoleic, but firmness of all ice creams was similar when measured between -17 and -13 degrees C. Nutritional and textural properties of butter and ice cream can be improved by modifying the diets of cows.     

Preparation and properties of ice cream type frozen yogurt

Changes in sensory ratings and chemical properties of ice cream type frozen yogurt (fat content >8.0% with varying pH values) were investigated during storage for 6 months at –35°C. No appreciable change was observed in the structure, acidity and pH values of the products during storage. In addition, there was no increase in thiobarbituric acid values of the products during storage. Viable lactic acid bacteria decreased in number with increasing storage period. Different sensory ratings were obtained for assessors who were familiar with yogurt and for assessors who were not. The product having a pH value of 5.5 was the most preferred ice cream type frozen yogurt in the products examined .     

辛烯基琥珀酸马铃薯淀粉酯在冰淇淋中的应用研究

将辛烯基琥珀酸马铃薯淀粉酯作为脂肪替代品代替配方中的奶油,进行了冰淇淋的制备试验。结果表明,冰淇淋配方为奶粉14%、白砂糖13%、蛋黄2%和复合稳定剂0.2%时,添加3.0%(w/w)该淀粉酯的无奶油冰淇淋制品其融化率下降、膨胀率提高,口感更加清凉、细滑;其它不同替代程度的低脂冰淇淋制品品质也较优良,整体品质明显优于添加3.0%(w/w)马铃薯原淀粉作为脂肪替代品制得的冰淇淋制品。结论为高黏度辛烯基琥珀酸马铃薯淀粉酯可以作为脂肪替代品部分或全部代替冰淇淋配方中的奶油,但相应冰淇淋的硬度略有增加。     

Properties of dextran as a cryoprotectant in ice cream

In order to determine the usefulness of dextran as a stabilizer in frozen dairy products, ice cream mixes with varying concentrations of this microbial polysaccharide were prepared and tested by sensory, physical and mechanical means. Although previous results had shown that aqueous solutions of dextran exhibited remarkably low viscosities, the addition of dextrans to ice cream mixes resulted in much higher values. This is thought to result from interactions among dextrans, dairy proteins and, perhaps, other stabilizers. Dextran addition effectively increased the T_g of ice cream mixes, indicative of its value as a cryoprotectant. Also, dextran significantly reduced the sensory perception of ‘iciness intensity’ in heat-shocked ice cream samples. This resulted from the ability of dextran to slow ice crystal growth during storage and thermal abuse, as indicated by reduced ice crystal size as compared to a control formulation. However, dextran also produced unwanted firmness and melting characteristics in ice cream that could influence commercial acceptability.     

The occurrence and growth of yeasts in dairy products

Yeasts were isolated, identified and enumerated from 161 samples of retail dairy products. Highest yeast populations (up to 10⁶–10⁷ cells/g) were found in yogurt and cheese samples while lower counts occurred in samples of pasteurized milk, cream, butter and ice cream. Candida famata, Kluyveromyces marxianus, Candida diffluens and Rhodotorula glutinis were the most frequency isolated species. The growth of these and other species was demonstrated during the refrigerated storage of cream, butter and cheese samples and by their inoculation and incubation in milk and yogurt samples. The predominance and growth species was probably related to their production of protein and fat hydrolysing enzymes and the ability to grow at 5°C.     

Preparation and evaluation of low‐calorie functional ice cream containing inulin,lactulose and Bifidobacterium lactis

This study was aimed to investigate the effects of replacing 5% fat and sugar by inulin and lactulose, respectively, on the survival of Bifidobacterium lactis and physicochemical and sensorial characteristics of the ice cream. Total solids, pH, melting rate and sensory scores of low‐fat and/or low‐sugar ice cream samples did not differ significantly from the control. Overrun and hardness of low‐fat samples were significantly higher than that of the control group (P < 0.01). The viable counts of B. lactis in the low‐sugar synbiotic ice creams were significantly lower than that of other groups at the end of 90‐day storage (P < 0.01).     

Effect of modified starch from sweet potato as a fat replacer on the quality of reduced fat ice creams

In the present study, application of different levels (0, 1 and 2%) of citric acid treated sweet potato starch as a fat replacer (FR) in a high (11% fat), medium (6% fat) and low-fat (1%) ice creams were investigated. Results indicated that hardness value tends to improve with the addition of 1% FR in all reduced fat ice creams. During 60 days of storage, a decreasing trend was noticed in overrun, acidity and hardness values of ice cream samples. Overall score of sensory conveyed that the reduced fat ice creams with 1% FR (medium fat ice cream and low fat ice cream) were found to be very acceptable by sensory panels with a similar physicochemical characteristics and acceptance as high-fat ice cream (control) at the end of storage period. Citric acid treated sweet potato starch proved to be a promising alternative as a fat replacer in the ice cream production.     

Properties of frozen dairy desserts processed by microfluidization of their mixes

Sensory properties and rate of meltdown of nonfat (0% fat) and low-fat (2% fat) vanilla ice creams processed either by conventional valve homogenization or microfluidization of their mixes were compared with each other and to ice cream (10% fat) processed by conventional valve homogenization. Mixes for frozen dairy desserts containing 0, 2, and 10% fat were manufactured. Some of the nonfat and low-fat ice cream mixes were processed by microfluidization at 50, 100, 150, and 200 MPa, and the remaining nonfat and low-fat ice cream mixes and all of the ice cream mix were processed by conventional valve homogenization at 13.8 MPa, first stage, and 3.4 MPa, second stage. The finished frozen and hardened products were evaluated at d 1 and 45 for meltdown rate and for flavor and body and texture by preference testing. Nonfat and low-fat ice creams that usually had a slower meltdown were produced when processing their mixes by microfluidization instead of by conventional valve homogenization. Sensory scores for the ice cream were significantly higher than sensory scores for the nonfat and low-fat ice creams, but the sensory scores for the conventional valve homogenized controls for the nonfat ice cream and low-fat ice cream were not significantly different from the sensory scores for the nonfat ice cream and low-fat ice cream processed by microfluidization of the mixes, respectively. Microfluidization produced nonfat and low-fat ice creams that usually had a slower meltdown without affecting sensory properties.     

Effects of Cinnamon (Cinnamomum Verum) Extract on Functional Properties of Butter

Butter is a dairy product made by churning fresh or fermented cream or milk. It is generally used as a spread and as an ingredient in cooking purposes. The incorporation of natural ingredients with health benefits into butter is one way to increase its intake. The potential health benefits of cinnamon (Cinnamomum verum) derived primarily from bioactive ingredients such as antioxidants, polyphenols and flavonoids. The objective of the present study was to improve the quality of butter made from cream with the addition of cinnamon extract. Milk cream with 36% fat was churned at 10oC to maintain the fat at high level with low moisture content. Based on preliminary investigation, soxhelt extraction of cinnamon quills was carried out with 39% (v/v) ethanol. Butter was prepared by incorporating cinnamon extract into butter at 1, 3, and 5% (w/w). Sensory evaluation was done using 20 semi trained panelists based on 5 point hedonic scale. It was found that cinnamon extract can be incorporated in to the butter formulation up to 3% (w/w) without compromising the sensory attributes. It was subjected to further analysis with 1000 ppm potassium sorbate added butter. Changes in peroxide value, free fatty acids value and pH were monitored at weekly intervals. Microbiological studies (Total plate count and yeast and mold) were done at two weeks interval during two months storage period. Storage stability was tested at refrigeration (4oC) condition. Total phenolic content and free radical scavenging activity of the 3% cinnamon extract incorporated butter were 135.62±1.00 μg GAE/mg and 38.73±0.01% DPPH, respectively. The cinnamon extract incorporated butter has shown low levels of peroxide value, free fatty acids value and low microbial count when compared to ordinary butter (without adding preservative) and potassium sorbate added butter. Antioxidant activity of cinnamon extends the shelf life of butter. This study demonstrates the 3% cinnamon extract can be used to formulate an antioxidant rich butter and it can be placed as a natural preservative for preparation of butter.     

丹贝冰淇淋的研制

利用正交试验探讨了丹贝粉、奶粉、人造奶油及瓜儿胶的添加量对丹贝冰淇淋膨胀率及感官质量的影响。结果显示，它们对丹贝冰淇淋的膨胀率和感官质量均有显著性的影响。当丹贝粉、奶粉、人造奶油及瓜儿胶的添加量分别为9.0%、5.0%、5.0%和0.2%时，冰淇淋的膨胀率和感官质量均达到最佳。     

自由基氧化的乳清蛋白在冰淇淋中的应用

研究经羟基自由基产生体系氧化后的乳清蛋白在冰淇淋中的应用,测定蛋白氧化的主要指标羰基含量,并对影响冰淇淋品质的主要参数(包括膨胀率、抗融性、保形性)以及感官指标进行评定。结果表明：在冰淇淋中添加经H2O2体系氧化后的乳清蛋白,产品各项指标明显好于添加FeCl3体系的冰淇淋,且能够提高产品的性能,尤其是添加氧化1h的氧化蛋白其感官评分达到最大,但同对照比口感略有降低。这说明,适当的氧化可以改进产品的品质,提高产品的可接受性,但需改进口感。     

SENSORY, CHEMICAL, AND PHYSICAL CHANGES IN INCREASED WATER ACTIVITY PEANUT BUTTER PRODUCTS

The effects of moisture, temperature, and storage time on the flavor characteristics of increased water activity peanut butter products were determined by sensory analysis. All three factors affected the sensory attributes of the products. At all temperatures and storage times, peanut butter products with 5.0% water added had lower roasted aroma and roasted flavor, with more off-odors and off-flavors than the 2.5% or 0.0% water added samples. Water activity and color were monitored throughout the study, and samples were evaluated for oxidation.     

Rheology of Ice Cream Mix Flavored with Black Tea or Herbal Teas and Effect of Flavoring on the Sensory Properties of Ice Cream

Rheological characteristics and physicochemical properties of ice cream mix flavored with black tea or some herbal teas and sensory profile of flavored ice cream was investigated. In this respect, black tea and three different herbal tea samples (sage, chamomile, and linden) were used to produce a new ice cream formulation. Some physicochemical properties and sensory characteristics of samples were determined. Total phenolic content of ice cream samples increased with the use of tea or herbal teas and it was in the range of 123.37–415.20 mg kg^?1. Incorporation of black tea and herbal tea except chamomile decreased the sensory scores of ice cream compared to control sample. The apparent viscosities of samples were measured as a function of shear rate and consistency coefficient and flow behavior index were calculated by using power law model. All ice cream mix samples showed non-Newtonian pseudoplastic behavior. The apparent viscosities of ice cream mixes treated with no tea at the shear rate of 50 s^?1 were 1.13, 0.91, and 0.76 Pa s at 10, 20, and 30 °C, respectively. The activation energy for the viscosity change of the samples ranged between 10.87–20.25 J?mol^?1 at 50 s^?1.     

Ice cream supplemented with grape juice residue as a source of antioxidants

Grape juice residue was incorporated into ice cream at 2.5%, 5.0% and 10.0% to obtain a product with functional characteristics. The chemical composition, colour, total phenolic compounds, antioxidant capacity and sensory acceptance of the ice creams were analysed at day 0 and after 40 days of storage. Ice creams containing grape juice residue had a higher concentration of phenolic compounds and antioxidant activity compared to the control samples. Consumers’ acceptance was similar for all products. At the end of storage, the polyphenol content and antioxidant activity had decreased. Grape juice residue has potential as a natural source of antioxidants to develop new products.     

Sensory quality of dairy products fortified with fish oil

Our objective was to evaluate the influence of fish oil fortification on the sensory quality of selected dairy products. Yoghurts, fresh, soft and processed cheeses, butter and cream were fortified at different levels. Sensory quality was evaluated using a scaling method and the threshold values of the fortification levels were established. Fortification of dairy products with long-chain polyunsaturated fatty acid (PUFA) omega-3 by fish oil addition appeared possible; however, the level of fortification was limited. The highest level of fortification was obtained for solid, high-fat dairy products (spreadable fresh cheese, butter and processed cheeses), especially when flavourings were present. Such dairy products maintained a constant sensory quality during 4 weeks of storage. One portion of butter, processed and spreadable fresh cheeses fortified at levels established in the study, might provide 180–360 mg of long-chain omega-3 PUFA, significantly elevating their average level in the diet.     

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.