Functional Properties of a Food Colorant Prepared from Red Cabbage

Spectral, colorant, and stability properties of colorants based on red cabbage, grape, cranberry, beet, and Red No. 40 were compared in buffer and in a simulated beverage. At pH 3, red cabbage imparted a red color similar to that of beet juice and less orange than that of the other colorants. Increasing the pH of red cabbage extracts to 4 produced a bathochromic shift and decreased color strength. Tristimulus parameters displayed maxima when L was varied. Red cabbage pigments were more stable during heating and storage than were the other colorants tested. pH had little effect on color stability; exposure to light greatly increased color loss during storage.     

Colorants in cheese manufacture: Production,chemistry, interactions,and regulation

Colored Cheddar cheeses are prepared by adding an aqueous annatto extract (norbixin) to cheese milk; however, a considerable proportion (～20%) of such colorant is transferred to whey, which can limit the end use applications of whey products. Different geographical regions have adopted various strategies for handling whey derived from colored cheeses production. For example, in the United States, whey products are treated with oxidizing agents such as hydrogen peroxide and benzoyl peroxide to obtain white and colorless spray‐dried products; however, chemical bleaching of whey is prohibited in Europe and China. Fundamental studies have focused on understanding the interactions between colorants molecules and various components of cheese. In addition, the selective delivery of colorants to the cheese curd through approaches such as encapsulated norbixin and microcapsules of bixin or use of alternative colorants, including fat‐soluble/emulsified versions of annatto or beta‐carotene, has been studied. This review provides a critical analysis of pertinent scientific and patent literature pertaining to colorant delivery in cheese and various types of colorant products on the market for cheese manufacture, and also considers interactions between colorant molecules and cheese components; various strategies for elimination of color transfer to whey during cheese manufacture are also discussed.     

Factors Affecting Pink Discoloration in Annatto-colored Pasteurized Process Cheese

The effects of cooking temperatures, cooling rates, pH, types of emulsifying salts, age of cheese, and sources of colorant were evaluated. Annatto emulsions showed less stability during continuous heating than annatto solutions or suspensions. Increased cooking temperatures resulted in slight decreases in Hunter a and b values, and overall decreases in hue angles. Emulsifying salt blends with increased amounts of sodium citrate resulted in decreased hue angles. Process cheeses made with more than 25% colored cheese showed lower hue angles than those samples made with uncolored cheese only. Whey powder as a source of added solids in process cheese food promoted discoloration, with acid whey resulting in the most pinking.     

Short communication: Annatto in Cheddar cheese-derived whey protein concentrate is primarily associated with milk fat globule membrane

The yellow color of Cheddar cheese whey arises from a residual amount of annatto that partitions into the whey during Cheddar cheese manufacture. Bleaching of the color using hydrogen peroxide or benzoyl peroxide is often a prerequisite to produce an acceptable neutral-colored whey protein concentrate and isolate. However, the use of these strong oxidizing agents often generates off-flavors as a result of lipid oxidation and results in loss of nutritive value due to protein oxidation. The objective of this study was to determine the extent of partitioning of annatto between protein, milk fat globule membrane (MFGM), and aqueous (serum) phases of cheese whey so that a simple method can be developed to remove annatto from cheese whey. The MFGM was separated from Cheddar cheese whey using a recently developed novel method. Quantitative analysis of the distribution of annatto in the fat-free whey protein isolate (WPI), the MFGM fractions, and the serum phase revealed that annatto was not bound to the protein fraction but was mostly distributed between the serum phase and the MFGM fraction. The results showed that a colorless WPI or whey protein concentrate could be produced from Cheddar cheese whey by separation of MFGM from the whey, followed by diafiltration. This approach will negate the need for using bleaching agents.     

The effect of starter culture and annatto on the flavor and functionality of whey protein concentrate

The flavor of whey protein can carry over into ingredient applications and negatively influence consumer acceptance. Understanding sources of flavors in whey protein is crucial to minimize flavor. The objective of this study was to evaluate the effect of annatto color and starter culture on the flavor and functionality of whey protein concentrate (WPC). Cheddar cheese whey with and without annatto (15 mL of annatto/454 kg of milk, annatto with 3% wt/vol norbixin content) was manufactured using a mesophilic lactic starter culture or by addition of lactic acid and rennet (rennet set). Pasteurized fat-separated whey was then ultrafiltered and spray dried into WPC. The experiment was replicated 4 times. Flavor of liquid wheys and WPC were evaluated by sensory and instrumental volatile analyses. In addition to flavor evaluations on WPC, color analysis (Hunter Lab and norbixin extraction) and functionality tests (solubility and heat stability) also were performed. Both main effects (annatto, starter) and interactions were investigated. No differences in sensory properties or functionality were observed among WPC. Lipid oxidation compounds were higher in WPC manufactured from whey with starter culture compared with WPC from rennet-set whey. The WPC with annatto had higher concentrations of p-xylene, diacetyl, pentanal, and decanal compared with WPC without annatto. Interactions were observed between starter and annatto for hexanal, suggesting that annatto may have an antioxidant effect when present in whey made with starter culture. Results suggest that annatto has a no effect on whey protein flavor, but that the starter culture has a large influence on the oxidative stability of whey.     

Effect of bleaching whey on sensory and functional properties of 80% whey protein concentrate

Whey is a highly functional food that has found widespread use in a variety of food and beverage applications. A large amount of the whey proteins produced in the United States is derived from annatto-colored Cheddar cheese. Color from annatto is undesirable in whey and must be bleached. The objective of this study was to compare 2 commercially approved bleaching agents, benzoyl peroxide (BP) and hydrogen peroxide (HP), and their effects on the flavor and functionality of 80% whey protein concentrate (WPC80). Colored and uncolored liquid wheys were bleached with BP or HP, and then ultrafiltered, diafiltered, and spray-dried; WPC80 from unbleached colored and uncolored Cheddar whey were manufactured as controls. All treatments were manufactured in triplicate. The WPC80 were then assessed by sensory, instrumental, functionality, color, and proximate analysis techniques. The HP-bleached WPC80 were higher in lipid oxidation compounds (specifically hexanal, heptanal, octanal, nonanal, decanal, dimethyl disulfide, and 1-octen-3-one) and had higher fatty and cardboard flavors compared with the other unbleached and BP-bleached WPC80. The WPC80 bleached with BP had lower norbixin concentrations compared with WPC80 bleached with HP. The WPC powders differed in Hunter color values (L, a, b), with bleached powders being more white, less red, and less yellow than unbleached powders. Bleaching with BP under the conditions used in this study resulted in larger reductions in yellowness of the powders made from whey with annatto color than did bleaching with HP. Functionality testing demonstrated that whey bleached with HP treatments had more soluble protein after 10 min of heating at 90°C at pH 4.6 and pH 7 than the no-bleach and BP treatments, regardless of additional color. Overall, HP bleaching caused more lipid oxidation products and subsequent off-flavors compared with BP bleaching. However, heat stability of WPC80 was enhanced by HP bleaching compared with control or BP-bleached WPC80.     

葡萄皮花色苷的树脂纯化及稳定性研究

以烟73酿酒葡萄为花色苷提取材料,采用HPLC分析方法,对10种树脂的吸附／解析效果进行了比较。选用性能较优的XAD-7HP树脂进行纯化实验并对纯化后花色苷的稳定性进行了研究。结果表明,纯化处理使花色苷在千物质中的含量由处理前的48．16％提高到处理后的94．93％,色价由处理前的47．7提高到处理后的291．6,回收率为85．7％。花色苷的稳定性实验结果表明,随着光照强度、温度、pH值的升高,花色苷的不稳定性明显加剧。在避光、pH值为3,4℃下存放7d,花色苷的保留率在95％以上,适宜于花色苷的短期保存。     

Pink Color Development in Turkey Meat as Affected by Nicotinamide, Cooking Temperature, Chilling Rate, and Storage Time

Consumers associate pink color in cooked turkey with undercooking. “Pinking” has been attributed to several factors, but remains a problem in the poultry industry. Effects of temperature, chilling rate, and storage time were investigated relative to pink color intensity of turkey meat cooked in the presence of 2% nicotinamide. As final cook temperature increased, sensory pinkness increased as did CIE a* values. Slower chilling rate resulted in higher CIE a* values and lower CIE b* values. Increased storage time generally increased CIE a* values and decreased b* values while CIE L* values were not affected.     

HPLC and spectrophotometric determination of annatto in cheese

A rapid and simple method for the detection of E 160b (annatto) in cheese and other milk products is described. After extraction with acetone, the two main components bixin and norbixin are separated from fat and #-carotene by solid-phase extraction (SPE). Both sample preparation and determination are made without halogenated solvents. For quantification of the annatto content, high-performance liquid chromatography (HPLC) and a spectrophotometric method were used. For the spectrophotometric method, extinction values of bixin and norbixin were determined in a mix of methanol and glacial acetic acid. The spectrophotometry is sufficient for the quantitative determination of the entire content of annatto. If the colorings E 100 (curcumine) or E 160f (#-apo-8'-carotenal) are present beside annatto, then HPLC is favored. Other food colors and emulsifiers do not disturb the determination. The correlation coefficient between the different methods was R²=0.9989. The recovery rates determined by spiking cheese, processed cheese, butter, and ice cream, were between 80 and 100%.     

Storage stability of lutein during ripening of cheddar cheese

Lutein (3,3'-dihydroxy-alpha-carotene) has been identified as a dietary factor that can delay the onset of age-related macular degeneration (AMD). However, available food sources of lutein contain only modest amounts of the carotenoid. Food fortification with lutein extract has been identified as a low-budget approach to prevent the onset or progression of AMD. The objectives of this study were to 1) incorporate various amounts of lutein into Cheddar cheese; 2) examine the color, pH, microbiological, and sensory characteristics of the Cheddar cheese during storage; and 3) analyze the stability of lutein during the cheese maturation process. Lutein extracted from corn was added to Cheddar cheese in quantities of 1, 3, and 6 mg per serving size. Measurements of the lutein stability were carried out by HPLC using a YMC C30 carotenoid column. Microbiological analyses of cheese samples included aerobic plate count, coliform, and yeast/mold counts. The color attributes a* and b* were significantly different between the treatment and control groups; however, no significant difference was observed in L* value and pH. Significant differences among 1, 3, and 6 mg lutein-enriched cheeses were observed in the aerobic plate count and yeast/mold compared with the control. Cheese samples contained no detectable levels of coliforms (< 10 cfu/g). The HPLC data showed quantitative recovery of lutein during the storage period, and no lutein degradation products were identified. These results indicate that lutein, a functional additive with purported ability to prevent or reduce the onset of AMD, can be incorporated into cheese adding value to this product.     

Blueberries as a Colorant Ingredient in Food Products

Frozen wild and cultivated blueberries were used as colorants at two levels in three model systems. Liquid beverage and condiment samples were measured by light transmission and read as Judd-Hunter L, a, b units. Opaque topping samples were measured by light reflection, recorded in L, a, b units with visual reference to Munsell Color System. Hue angle theta was calculated for all samples. Pigment analyses were done by acid-ethanol extraction and calculated as cyanidin-3-glucoside. Lower pH model systems had redder color; higher pH products had bluer color. Wild blueberries had high pigment content. The color was related to the pigment content.     

Stability of polyhydroxylated 1,4‐naphthoquinone pigment recovered from spines of sea urchin Strongylocentrotus nudus

The stability of polyhydroxylated 1,4‐naphthoquinone pigment recovered from sea urchin (Strongylocentrotus nudus) spines was observed by spectrophotometer. When pH values changed from 2.0 to 10.0, the pigment showed colour variations. Meanwhile, pH values affected the stability of the pigment. After 24 h of storage, the pigment remained 95.64%, 79.68% and 46.15% of the initial absorbance at pH 3.0, 7.0 and 10.0, respectively. The pigment was prone to degrade on exposure to light. It remained 40.11% of the initial absorbance under natural light after 14 days of storage. Whereas the corresponding value in the dark was 65.14%. Degradation rate of the pigment increased with increasing temperature. The pigment remained 90.49% of the initial absorbance at 20 °C after 24 h of storage. However, the corresponding value decreased to 66.61% at 80 °C. Additives, including antioxidant, oxidising and reducing agents, and some metal ions all affected the stability of the pigment.     

Pathogen inactivation and quality changes in sliced cheddar cheese treated using flexible thin-layer dielectric barrier discharge plasma

Cheese is recognized as a source of food-borne disease outbreaks worldwide. In this study the inactivation of pathogens on sliced cheddar cheese by using flexible thin-layer dielectric barrier discharge (DBD) plasma and its effect on food quality have been described. Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella Typhimurium populations on agar plates were significantly reduced by plasma treatment. The level of these microorganisms on sliced cheddar cheese in response to 10-min plasma treatment significantly decreased by 3.2, 2.1, and 5.8 Log CFU/g, respectively. The pH and L*-values decreased whereas thiobarbituric acid reactive substances values and b*-values increased significantly with extended exposure of the sliced cheddar cheese to DBD plasma. The total color difference (∆E), sensory appearance and color scores showed no significant differences between DBD plasma-treated and untreated sliced cheddar cheese. However, significant reductions in flavor and overall acceptance as well as an increase in off-odor were observed. These results indicate that flexible thin-layer DBD plasma can be used to sanitize food products, but conditions should be optimized for industrial applications.     

Encapsulation of bixin in sodium caseinate to deliver the colorant in transparent dispersions

Bixin, the major colorant component of annatto, is water insoluble and sensitive to degradation by temperature, pH, and light stresses. In this work, we studied an encapsulation process by spray drying warm 40% v/v aqueous ethanol solution with dissociated sodium caseinate (NaCas) and dissolved bixin. Upon hydration of spray-dried powder, transparent dispersions were observed at a wide pH range away from the isoelectric point (pI) of NaCas. The stability of bixin was much improved and the consistent yellow color was obtained. The volume–length mean particle diameters of capsules were around 250 nm in dispersions, slightly bigger than that of NaCas, based on dynamic light scattering, but the difference was not observed based on atomic force microscopy. Capsules and the mixture of NaCas and bixin showed different fluorescence and FTIR spectra. At pH near the pI of casein, soluble soybean polysaccharides adsorbed strongly onto capsules and stabilized them from aggregation. The simple encapsulation approach studied in the present work showed a promising process to enhance the stability and dispersibility of carotenoids using NaCas as a carrier, especially in transparent dispersions.     

Response surface models used for prediction of photooxidative quality changes in havarti cheese

Light-induced oxidation during cold display storage of modified atmosphere-packaged, sliced Havarti cheese was evaluated in a study introducing low levels of residual oxygen (0.01, 0.2, 0.5, and 1%), varying product-to-headspace ratios (1:4, 1:1.5, and 1.5:1) as well as light/dark storage. Irrespective of product-to-headspace ratio, equilibrium concentrations of oxygen were reached within 70 h, with lowest concentrations found for the highest product-to-headspace ratio. The changes in oxygen during light exposure were in compliance with the color measurements, which showed an increase in a* values and a decrease in b* values during light exposure, with a resultant biphasic change in the hue of the cheeses. Analysis of volatile secondary oxidation products determined by solid-phase microextraction GC/MS revealed an increase in 1-pentanol and 1-hexanol during light-exposed display when residual oxygen levels were augmented, which in effect led to severe quality deterioration as verified by odor analysis. No effect of product-to-headspace volumes was noted. Based on changes in concentrations of 1-pentanol and 1-hexanol, explorative response surface models describing the relationship between secondary oxidation product formation and residual oxygen contents were developed. The response surface models presented may subsequently form the basis for selecting optimal packaging conditions in relation to photooxidation in sliced Havarti cheese, and similar approaches are expected to be applicable to other dairy products.     

Survival and acid resistance of Listeria innocua in Feta cheese and yogurt, in the presence or absence of fungi

The objective of the study was to assess the survival of Listeria innocua, alone or coinoculated with fungal isolates, during storage of Feta cheese (pH 4.43 to 4.56) and yogurt (pH 4.01 to 4.27) at 3 to 15 degrees C. The acid resistance of the bacterium during subsequent exposure to pH 2.5 for 3 h was also evaluated in samples stored at 3 and 10 degrees C. In Feta cheese, L. innocua survived better than it did in yogurt at all temperatures. At 5, 10, and 15 degrees C, the pH of cheese increased due to fungal growth, and this enhanced the survival of L. innocua more than during storage at 3 degrees C. Moreover, during storage of Feta cheese, L. innocua was capable of surviving the subsequent exposure for 3 h in broth of pH 2.5, in contrast to cultures not inoculated in the product (control cultures; 24 h at 30 degrees C in broth). In yogurt, L. innocua reduced more than 5 log within 15 days of storage at 5, 10, and 15 degrees C, whereas extended survival was observed at 3 degrees C until day 22, with total reduction of approximately 4.5 log. In contrast to what was observed in Feta cheese, surviving populations of L. innocua in yogurt were eliminated after subsequent exposure for 3 h to pH 2.5. The findings indicate that growth of fungi on the surface of Feta cheese and yogurt may compromise the safety of these products by enhancing survival of the bacterium. Particularly, when fungi increase the pH of Feta cheese, L. innocua demonstrates better survival and prolonged storage may raise concerns for the development of acid-resistant Listeria populations.     

Effect of Cheese pH and Temperature on Serum Phase Characteristics of Cream Cheese During Storage

Three 13.6‐kg blocks of cultured cream cheese manufactured on different days were obtained from a commercial source within 2 wk of manufacture. Blocks were sectioned into samples that were randomly assigned to 3 treatments. A model system was used to change cheese pH. One group of samples was exposed to volatile ammonia to increase the pH to about 5.3. A 2nd group was exposed to volatile acetic acid to decrease the pH to about 4.5. A 3rd group served as a control (pH about 4.8). Samples from each pH treatment were vacuum‐packaged and randomly assigned to 1 of 2 storage temperatures: 4 °C and 20 °C. Samples were randomly chosen for analysis after 4, 8, 12, 16, 20, 24, and 28 d of storage and centrifuged at 12500 ±g for 75 min at 25 °C to obtain expressible serum (ES). The ES was analyzed for viscosity at 25 °C. Effects of pH treatment, storage time, and storage temperature were evaluated by analysis of variance (ANOVA) according to a split split‐plot design. The amount of ES increased significantly during storage and was affected by storage temperature and cheese pH. Significantly more ES was obtained at higher temperature and higher pH. Viscosity of ES decreased significantly during storage and was affected by storage temperature and cheese pH. Viscosity decreased more rapidly at higher temperature and higher pH. The data suggest that higher temperature and higher pH resulted in accelerated loss of stabilizer function during storage, possibly due to microbiological degradation of the stabilizer.     

Storage stability of sterilized liquid extracts from pomegranate peel

Pomegranate marc, a byproduct of commercial juice production, has shown promise as a starting material for the recovery of health promoting phenolic compounds. The stability of aqueous extracts prepared from pomegranate marc was evaluated in preparation to directly using these extracts as nutraceuticals or food additives. The liquid extracts were produced under extraction conditions of 25 °C, water to peel ratio of 50 : 1 (w/w) for 2 min, and then sterilized at 121 °C for 10 s. Storage conditions tested included 3 different pH values (3.5, 5.0, and 7.0) and 2 packaging methods (no light and exposure to light). The extracts were evaluated for industrial (pH, total soluble solid content, and clarity), color, spectral, and antioxidant characteristics over a period of 180 d. The results showed that both pH value and packaging method significantly influenced the industrial and color characteristics of the extracts. The high pH had a negative effect on spectral and antioxidant characteristics. Therefore, the recommended storage conditions are low pH and with dark packaging to maintain the high storage stability. After 180 d of storage, extracts stored at low pH (3.5) in dark packaging still retained 67% and 58% of their total soluble phenolic concentration and antioxidant activity, compared with 61% and 43% for high pH (7.0) samples, and were composed of high concentrations of punicalagins A and B, gallic, and ellagic acids. PRACTICAL APPLICATION: The present research developed an effective recovery of phenolic compounds from pomegranate marc to be used as nutraceuticals or food additives. The aqueous extract product has good quality characteristics with high industrial and color stability, and total phenolic content and antioxidant activity, when stored at pH 3.5 in dark packaging for up to 180 d. The evaluation results of storage stability reported here are important for commercialization.     

Short communication: Norbixin and bixin partitioning in Cheddar cheese and whey

The Cheddar cheese colorant annatto is present in whey and must be removed by bleaching. Chemical bleaching negatively affects the flavor of dried whey ingredients, which has established a need for a better understanding of the primary colorant in annatto, norbixin, along with cheese color alternatives. The objective of this study was to determine norbixin partitioning in cheese and whey from full-fat and fat-free Cheddar cheese and to determine the viability of bixin, the nonpolar form of norbixin, as an alternative Cheddar cheese colorant. Full-fat and fat-free Cheddar cheeses and wheys were manufactured from colored pasteurized milk. Three norbixin (4% wt/vol) levels (7.5, 15, and 30 mL of annatto/454 kg of milk) were used for full-fat Cheddar cheese manufacture, and 1 norbixin level was evaluated in fat-free Cheddar cheese (15 mL of annatto/454 kg of milk). For bixin incorporation, pasteurized whole milk was cooled to 55°C, and then 60 mL of bixin/454 kg of milk (3.8% wt/vol bixin) was added and the milk homogenized (single stage, 8 MPa). Milk with no colorant and milk with norbixin at 15 mL/454 kg of milk were processed analogously as controls. No difference was found between the norbixin partition levels of full-fat and fat-free cheese and whey (cheese mean: 79%, whey: 11.2%). In contrast to norbixin recovery (9.3% in whey, 80% in cheese), 1.3% of added bixin to cheese milk was recovered in the homogenized, unseparated cheese whey, concurrent with higher recoveries of bixin in cheese (94.5%). These results indicate that fat content has no effect on norbixin binding or entrapment in Cheddar cheese and that bixin may be a viable alternative colorant to norbixin in the dairy industry.