Colour stability of canned strawberries using black carrot and elderberry juice concentrates as natural colourants

Besides texture degradation and aroma loss colour fading and browning of processed fruits, in particular strawberries, displaying comparatively low amounts of non-acylated anthocyanins, still pose a serious problem. Therefore, in the present study the colour of texture-improved canned strawberries was stabilised using commercial concentrates from black carrots and elderberries as natural colourants. CIE L ^* a ^* b ^* values of the fruit surface and of the brine solutions were monitored over a period of 24 weeks under light exposure. Furthermore, the contents of individual anthocyanins were analysed by HPLC-DAD. The colour of the processed control fruits (without added colourant) was unacceptable even at the beginning of the storage. Their anthocyanin contents were reduced by more than 85% at the end of the storage period. In contrast, the colour of canned strawberries containing black carrot and elderberry anthocyanins was significantly improved. Colour difference values ΔE ^* of black carrot-coloured strawberries were found to be smaller than those of the samples containing elderberry concentrate as a colourant. This could be ascribed to the presence of acylated anthocyanins in the first exhibiting exceptional storage stability, while all non-acylated pigments were degraded. The chill brining process for fruit firming markedly affected pigment stability, which can be attributed to enzymes that are still active at cold storage conditions.     

Consumer Acceptance of Model Soup System with Varying Levels of Herbs and Salt

Although herbs have been reported as one of the most common saltiness enhancers, few studies have focused on the effect of herbs on reducing added sodium as well as the impact of herbs on consumers’ overall liking of foods. Therefore, the objectives of this study were to determine the effect of varying levels of herbs on reducing added sodium and consumers’ overall liking of soups and identify the impact of salt levels on consumers’ overall liking of soups. Overall liking of freshly prepared and retorted canned soups with varying levels of herbs was evaluated before and after adding salt by consumers ad libitum until the saltiness of the soup was just about right for them. The results of the study demonstrated that when the perceived herb flavor increased, the amount of salt consumers added to fresh soups decreased (P ≤ 0.006); however, consumers’ overall liking decreased (P ≤ 0.013) as well for the highest level of herb tested in the study. Although overall liking of all canned soups was not significantly decreased by herbs, the amount of salt consumers added was also not significantly decreased when herbs were used. Overall liking of all soups significantly increased after more salt was added (P ≤ 0.001), which indicates that salt level was a dominant factor in affecting consumers' overall liking of soups with varying levels of herbs. These findings imply the role of herbs in decreasing salt intake, and the adequate amount of herbs to be added in soup systems.     

THE CONTRIBUTION OF HERBS TO THE ACCUMULATION OF HISTAMINE IN "OTLU" CHEESE

The aim of this study was to determine the effect of herbs and the use of raw milk on histamine accumulation in “Otlu” (Herby) cheese during ripening. Cow's milk was used for the cheese production. The milk was divided into two main groups: one was used raw and the other was pasteurized at 65C for 30 min. Each group was further divided into two subparts, one of which was used as control (without herbs), while 2% (w/v) of the herbs were added into the other to produce Herby cheese. All cheeses were ripened at 7C for 90 days. The cheese samples were analyzed in terms of histamine content, titratable acidity, dry matter, salt and degree of ripening on days 5, 30, 60 and 90. Total mesophilic aerobic bacteria (MAB) were also counted during ripening. The use of raw milk and the addition of herb both increased histamine formation in Otlu cheeses (P < 0.05). Moreover, higher water‐soluble nitrogen values, as degree of ripening, were obtained from both raw milk and herb‐added cheeses. The number of MAB was higher in raw cheeses (P < 0.05) and also herb‐added cheeses. The study suggests that the addition of herbs may facilitate histamine formation in Herby cheese.     

Effect of Lactococcus lactis Immobilized Within Pineapple and Yam Bean Segments, and Jerusalem Artichoke Powder on Its Viability and Quality of Yogurt

Lactococcus lactis cells were immobilized within pineapple segments, yam bean segments, and Jerusalem artichoke (JA) powder, and immobilized cells were used separately as adjuncts in producing probiotic yogurt. In parallel, yogurt with free L. lactis cells and yogurt only from starter cultures were also produced. The resulting yogurt samples were stored at 4 °C. Immobilization of cells increased the viability of L. lactis cells compared to free cells during storage of yogurt within pineapple segments, JA powder, yam bean segments, and free cells (43.77 %, 63.62 %, 80.11 %, and 87.14 %, respectively). The pH values of all yogurt samples decreased during storage; however, the pH values of yogurt supplemented with immobilized cells were higher than samples with free L. lactis cells. The increase in lactic acid content during storage was not different among the yogurt samples with added immobilized cells within segments of pineapple, yam beans, and free cells. However, the lactic acid content increase was greater with samples containing immobilized cells within JA powder. The immobilized cells within pineapple segments resulted in a decrease in b* color values (indicating yellowness) and an increase in a* color values (indicating greenness) whereas immobilized cells within yam bean segments resulted in a decrease in b* color values. Immobilized cells within JA powder resulted in a decrease in L* color values (indicating lightness) and an decrease in a* color values when compared to free cells. During storage, the concentration of γ-aminobutyric acid had a tendency to increase, which was not statistically significant. The sensory test revealed that the overall acceptance scores of yogurt with immobilized cells added were quite similar to those of the samples with free cells and controls throughout the storage period of 28 days.     

Effects of fat reduction and fat replacer addition on some quality characteristics of frankfurter-type sausages

Some quality characteristics of frankfurters manufactured in three different fat levels (20%, 10% and 5%) and added citrus fibre (CF) and soy protein concentrate (SPC) were investigated. While moisture content of frankfurters increased with decreasing fat levels, protein contents increased. Lower fat levels resulted in lower water‐holding capacity (WHC), cooking losses and penetrometer values. Lower L* values and higher a* values were obtained in low fat frankfurters. SPC significantly increased the cooking losses in the sausages with 5% and 20% fat, but decreased in the sausages with 10% fat. The lower cooking loss values were obtained in sausages added CF for all fat levels. Addition of fat replacers decreased the L values but did not affect the a and b values. Addition of fat replacers increased hardness in case of low fat levels. The softer product was obtained with high‐fat formulation than low‐fat formulation. Lower taste scores were observed with addition of fat replacers.     

Preparation and properties of probiotic concentrated yoghurt (labneh) fortified with conjugated linoleic acid

Milk of high conjugated linoleic acid (CLA) level (1.25 g per 100 g milk fat) was produced by inclusion of fish oil and rousted soy bean in the ration of Holstein cows as compared to 0.55 g per 100 g milk fat in the milk of animals receiving control diet. Milk of normal (control) and high CLA content (treatment) was spray‐dried. Labneh was made from 20 g L^?1 reconstituted milk using 3 mL per 100 mL yoghurt starter and 2 mL per 100 mL of probiotic cultures of Lactobacillus casei or Lactobacillus acidophilus. The control (C) and high CLA (T) labneh were analysed chemically and microbiologically, and their viscosities were determined during cold storage for 15 days. The fat content of labneh of high CLA was less than that of the control, but the total solids (TS) were unaffected by the CLA level. Labneh made with Lb. acidophilus had lower TS and higher acidity, exopolysaccharides and acetaldehyde contents and viscosity than that made with the use of Lb. casei. Labneh from the different treatments retained high counts of the added probiotic (>10⁸ cfu g^?1) throughout the storage period. The storage period had significant effects on all parameters determined.     

The effect of mendi (Chaerophyllum sp.) on ripening of vacuum-packed herby cheese

The composition, biochemical and sensory parameters of control cheese (without herbs) and four herby cheeses at 0.5, 1, 2 and 3% herb levels (mendi, Chaerophyllum sp.) ripened at 4 ± 1°C for 90 days were compared. As herb levels increased from 0.5 to 3%, dry matter and pH value decreased significantly. However, dry matter of all cheeses showed similar changes during ripening. The salt content of samples changed from 3.44 to 5.47% during ripening. There was a tendency toward slightly higher titratable acidity in cheeses with more added herbs. Ripening index, trichloroacetic acid-soluble nitrogen/total nitrogen, phosphotungstic acid-soluble nitrogen/total nitrogen, and lipolysis values of the cheese samples were affected by adding herbs and by ripening time. The most acceptable sensory score was obtained with 1% added herbs.     

Effect of banana and soybean hull flours on vacuum‐packaged chicken nuggets during refrigeration storage

The green banana flour (GBF), soybean hull flour (SHF) and combination (50:50) of GBF and SHF were added at the level of 4% each to evaluate the storage characteristics of chicken nuggets. The pH values were declined (P < 0.05) over storage periods. Lipid oxidation products were higher (P < 0.05) in control samples; however, they were increased in all samples with the increase in storage time. GBF‐added samples had lower (P < 0.05) free fatty acid contents when compared to other treated nuggets including control. With respect to microbial quality, standard plate counts, psychrotrophic counts and Lactobacillus spp. counts were increased (P < 0.05) with the storage periods. Total coliforms, Staphylococcal spp. and Yeast and mould counts were detected sporadically. Result of sensory evaluation indicates that scores for all attributes were declined gradually with storage time, and slight off‐flavour was noticed on the day 45. So, chicken nuggets developed with GBF and SHF could have shelf life in between 36 and 45 days at 4 ± 1 °C under vacuum‐packaging conditions.     

Packaging and Storage Effects on Microbiological Quality of Dried Herbs

Two hundred herb samples were investigated for microbiological quality. Effects of drying method, type package, and storage conditions were determined for dill, basil, marjoram, and wild marjoram. Total aerobic count ranged from 10⁴ to 10⁷/g dried material. Molds and aerobic sporeformers, especially Bacillus cereus, were detected in most samples; fecal indicator organisms were found infrequently. The number of most vegetative microbes was affected by the drying method. Microbes survived air-drying better than freeze-drying. Packaging affected microbial content. The lethal effect of storage time was most clearly shown when the herbs were packed in oxygen-containing packages.     

Effects of Rosemary Extract and Sodium Lactate on Quality of Vacuum-packaged Ground Ostrich Meat

ABSTRACT Vacuum‐packaged ground ostrich meat patties containing 2% sodium lactate (SL), 0.2% rosemary extract as oleoresin (RE), or their mixture (MIX) were evaluated and compared with control for their storage stability at 3 ± 1 °C in the dark by measuring pH, 2‐thiobarbituric acid‐reactive substance (TBARS) values, sample color (CIE L*, a*, b*, Hue and Chroma), and microbiological content. The pH values of ostrich patties, ranging from 6.03 to 6.13, were not affected by treatment (P < 0.05). At 9 d of storage, TBARS concentration for control samples containing no additives was 1.64 mg malonaldehyde/kg meat. Addition of RE to the ground ostrich meat inhibited lipid oxidation during storage at 3 ± 1 °C (P < 0.05). TBARS values of SL‐added samples were lower than control samples (P < 0.05); addition of SL also delayed the oxidation. It was found that RE had a protective effect on color, whereas addition of SL decreased CIE a* values (P < 0.05). SL, either alone or with RE, was effective in inhibiting total aerobic bacteria (TAB), coliforms, lactic acid bacteria (LAB), and Brochothrix thermosphacta in ostrich patties (P < 0.05) and provided a 2‐log reduction in microbial population during storage. In addition, RE did not have a significant effect on microbial growth at the concentration used in this study.     

The effects of some herbs on the activities of thermophilic dairy cultures

In this study, the effects of some herbs (Allium sp., Thymus sp., Anhriscus sp. and Ferule sp.) on growth and acid production of thermophilic cultures (Streptococcus thermophilus and Lactobacillus bulgaricus) were determined. The herbs were sterilized with gamma radiation and added to fermentation media at concentrations of 0.5, 1, 2 and 3% (w/w). Control medium was without herb. Results showed that increasing herb concentrations stimulated acid production by Streptococcus thermophilus and Lactobacillus bulgaricus.     

The effect of pumpkin fibre on quality and storage stability of reduced‐fat set‐type yogurt

In this study, the effect of pumpkin fibre (PF) on physicochemical, microbiological, rheological and microstructural characteristics of reduced‐fat yogurt samples was investigated during storage. PF was added at three different concentrations (0.5%, 1.0% and 1.5%) to standardised (1.55% fat ratio) cow's milk. Plain yogurt (PF‐free) was used for comparison. The addition of PF significantly affected total solid content, synaeresis, water‐holding capacity, apparent viscosity and colour parameters (L*, a*, b*) of yogurt samples for all sampling time. The addition of PF caused a reduction in L* values (from 94.89 to 88.67), but caused an increase in a* (from ?2.10 to +4.22) and b* (from 10.79 to 25.88) values. Yogurts with PF exhibited lower synaeresis and more viscous structure than PF‐free sample during storage. SEM images showed that distinctive microstructure profile was present between samples with or without PF. More filamentous structures and denser network were observed in the SEM images and these increased with increasing level of PF. Yogurt containing 1.0% PF showed a higher storage (G′) (3687.87 at 21 day) and loss (G″) (543.10 at 21 day) moduli in comparison with other samples. In conclusion, the results revealed that PF improved the physical quality and contributed textural properties of half‐fat yogurt.     

Retail Shelf-Life of Pork Dipped in Organic Acid before Modified Atmosphere or Vacuum Packaging

Modified atmosphere packaging (MAP) is increasingly popular for meat, but raw, chilled pork in vacuum or anoxic environments has a purple color. The retail shelf‐life of pork chops dipped in 500 ppm ascorbic acid, 250 ppm citric acid, or no acid dip and stored at 1 °C before simulated retail display in MAP with gas exchange or air‐permeable packaging after vacuum pouch storage was determined. The 80% N₂:20% CO₂ in MAP was exchanged with 80% O₂:20% CO₂, and chops were removed from vacuum packages and overwrapped with permeable film (VP‐PVC) on the 7th day before simulated retail display at 4 °C. Shelf‐life traits were determined at 1, 7, 8, 10, 12, and 14 d postpackaging. The pH values changed with time, but returned to post‐dipped, prepackaged levels at the end of simulated retail storage. Weight loss of chops increased (P < 0.05) in VP‐PVC compared with MAP. The a* values increased (P < 0.05) and L* and b* values decreased during simulated retail display, with higher L*, a*, and b* color values for chops in MAP than VP‐PVC. Log numbers of psychrotrophic microorganisms were higher (P < 0.05) on VP‐PVC samples than for chops in MAP on days 12 and 14. Psychrotrophic counts on ascorbic acid‐treated samples were decreased compared with citric acid or no dipping on pork during simulated retail display. Pork chops in MAP with gas exchange had lighter and redder color, increased weight retention, decreased psychrotrophic counts, and increased lipid oxidation compared with conventional vacuum and overwrap packaging systems.     

Effects of Elevated Temperature Postharvest on Color Aspect,Physiochemical Characteristics,and Aroma Components of Pineapple Fruits

In this work, 2 separate experiments were performed to describe the influence of elevated temperature treatments postharvest on the color, physiochemical characteristics and aroma components of pineapple fruits during low‐temperature seasons. The L* (lightness) values of the skin and pulp of pineapple fruits were decreased. The a* (greenness‐redness) and b* (blueness‐yellowness) values of the skin and pulp were all markedly increased. The elevated temperature significantly increased the contents of total soluble solids (TSS) and slightly affected contents of vitamin C (nonsignificant). Titratable acidity (TA) of pineapple fruits were notably decreased, whereas the values of TSS/TA of pineapple fruits were significantly increased. The firmness of the pineapple fruits decreased and more esters and alkenes were identified. The total relative contents of esters were increased, and the total relative contents of alkenes were decreased.     

Sensory and Nutritional Quality of Split Peas (Pisum Sativum) Stored up to 34 Y in Residential Storage

ABSTRACT: The sensory and nutritional quality of split peas stored up to 34 y was determined. Nine samples of split peas representing 5 retail brands packaged in Nr 10 cans and stored at room temperature were obtained from donors. Duplicate cans of a fresh sample of split peas were purchased as controls. Can head space oxygen ranged from 0.255% to 20.1%. Water activity of the raw split peas ranged from 0.41 to 0.56. The green color of the raw split peas decreased over time as shown by increasing CIE a* values. Flavor, appearance, texture, and overall liking hedonic scores (9-point scale) of split-pea soup made from each sample ranged from 3.7 to 6.7 and decreased over time. Hedonic scores for appearance were correlated with the decrease in raw product green color (r²= 0.65). Hedonic scores for soup texture declined over time, which corresponded with increasing hardness of the cooked peas as measured by a TA.XT2 texture analyzer. All samples were judged to be acceptable in an emergency situation by over 75% of sensory panelists. Available thiamin was significantly lower in older samples while riboflavin remained unchanged. The results indicate that split pea quality declines over time, but the product maintains sufficient sensory acceptance to be considered for potential use in emergency storage and other applications where minimal stock rotation is a common practice.     

Effects of gas composition in modified atmosphere packaging on the meat quality of Spanish Manchega lamb

The effects of four types of packaging atmosphere, each with a different gas composition (20–80% CO₂), on the meat quality of Spanish Manchega lamb were examined in order to suggest a gas composition for optimal preservation. Meat quality was assessed by pH, colour (L*,a* and b* values), water‐holding capacity (WHC), cooking loss (CL) and shear force (SF). Gas composition affected all parameters except L* and SF. The pH values decreased significantly in samples packed with 80% CO₂ but remained constant in the other groups. The b* values were lower in samples packed without O₂ than in the other groups and increased with time. However, the a* values decreased in all groups with time. Samples packed in low‐CO₂ atmosphere tended to lose more water (ie to have less WHC and show more CL). The SF values decreased with time, and similar values of this parameter were observed for all treatments. © 2001 Society of Chemical Industry     

Comparison of Milk Mineral, Sodium Tripolyphosphate, and Vitamin E as Antioxidants in Ground Beef in 80% Oxygen Modified Atmosphere Packaging

The antioxidant effects of milk mineral (MM), sodium tripolyphosphate (STP), and vitamin E (E) were tested in raw ground beef packaged in 80% O₂ modified atmosphere packaging, and held 1, 4, 7, or 14 d at 2 °C. Two levels of each antioxidant (0.75% and 1.5% MM, 0.25% and 0.5% STP, 50 or 100 ppm E) were compared with control samples without added antioxidants. Vitamin E was mixed with mineral oil or ethanol before mixing with meat samples. Thiobarbituric acid (TBA) values were highest (P < 0.05) in controls without antioxidants, and samples with added vitamin E. Lowest TBA values (<0.5) were in samples treated with 0.75% or 1.5% milk mineral. All ground beef samples maintained redness (a* > 10) through 4 d of storage. By day 7, ground beef treatments with added E were brown. After 14 d, ground beef with 0.75% MM was more red (P < 0.05) than other treatments or controls. Thus, 0.75% MM has possible application to prolong red color stability and inhibit lipid oxidation in ground beef packaged in high oxygen atmospheres.     

Effects of processing and storage on juice colour and betacyanin stability of purple pitaya (<Emphasis Type="Italic">Hylocereus polyrhizus</Emphasis>) juice

Purple pitaya (Hylocereus polyrhizus) fruits have been recently proposed as a promising source of betalains. In the present study, purple pitaya juice processing at pilot-plant scale is reported for the first time. Each processing step was examined in terms of juice colour and betacyanin retention. Lightness (L ^*) and hue angle (h°) values were strongly influenced by juice filtration, while chroma (C ^*) and betacyanin retention were most strongly altered by pasteurisation. Three systems of juice pasteurisation were evaluated. Betacyanin loss and colour alteration were minimal upon pasteurisation in an HTST system and a standard tubular heat exchanger, respectively. Additionally, storage experiments using mucilage-free purple pitaya juice were conducted. Whereas light exposure of unsupplemented samples resulted in significant pigment degradation, detrimental effects of light exposition were completely prevented by the addition of 1% ascorbic acid prior to storage. After 6 months, about 70% of the initial betacyanin content was retained in the presence of ascorbic acid, irrespective of illumination.