Comparative stability of aspartame and neotame in yoghurt

The comparative stability of aspartame and neotame was monitored in yoghurt during its processing, fermentation and storage. A solid‐phase extraction method was suggest changing it to developed for the isolation of aspartame and neotame. Pasteurisation (85 °C/30 min) resulted in approximately 47% and 3% loss of aspartame and neotame, respectively. During fermentation, 3% loss of aspartame was observed, but no loss of neotame. There was no significant effects on the stability of either aspartame or neotame during storage (4–7 °C/15 days). The results indicated that neotame was more stable than aspartame under both pasteurisation and fermentation conditions; however, during storage, both sweeteners exhibited excellent stability.     

Rheological,microstructural and sensory characterization of low-fat and whole milk set yoghurt as influenced by inulin addition

The effect of inulin addition (0–4%) upon texture and microstructure of set yoghurt with different levels of fat (0.2%–3.5%) was investigated. A two-factor experimental design with four treatments was used for data analysis. Skimmed milk with various inulin and cream concentrations was standardized to 4% protein content, homogenized, heated to 92 °C and fermented at 42 °C until a pH of 4.6 was reached. The chemical composition, pH, consistency and microstructure properties of the yoghurts were analysed after 6 days of storage at 5 °C. The statistical analysis showed that inulin and fat significantly affected the rheological and sensory results. Higher yield stress, “firmness” and “creaminess” values were observed in yoghurt produced with higher inulin additions, whereas the pH value was not affected. A significant correlation was found between yield stress and sensory determined firmness (r = 0.91). The microstructure examined by confocal laser scanning microscopy (CLSM) was only slightly affected by the concentrations of inulin in the range studied, possibly due to weak protein interactions between the inulin and the milk protein network.     

Calcium–inulin wheat bread: prebiotic effect and bone mineralisation in growing rats

The nutritional performance of wheat bread prepared with calcium carbonate and inulin was studied in growing rats fed with three diets (BD: diet containing bread with calcium and inulin, SD: diet with synergy1^® and CD: diet control‐AIN 93G‐) up to 60 days. Animals fed with BD consumed less diet and presented a caecal pH (5.5) lower than that of the CD group (7.0) with the highest amount of anaerobic micro‐organisms (1.68 × 10¹⁰ cfu g^?1) at 23 days. Microbiota profiles (DGGE) indicated that BD groups presented 66% of similarity and greater variability than the CD group, suggesting changes due to the prebiotic effect of inulin. In the BD group, calcium apparent absorption (AA_Ca: 83%), bone mineral content (18 g kg^?1), proximal tibia density (242 mg cm^?2) and bone volume (BV: 41%) were higher than in the CD group. The decrease in pH due to fermentation in the large intestine increased calcium bioavailability. Although all variables studied on animals fed with diets containing the prebiotic were improved with respect to a control without inulin, in the case of bread diet, many of them were similar to those of the positive control. Consequently, the prebiotic effect was not altered during the baking process. Results suggest that wheat bread, a highly consumed product throughout the world, is an adequate vehicle for including calcium and inulin in healthy food.     

Effect of nutrient supplements on growth and viability of Lactobacillus johnsonii NRRL B-2178 in whey

The main objectives of the paper were to study the effects of nutrient supplementation of cows' whey on the growth and viability of the probiotic microorganism Lactobacillus johnsonii NRRL B-2178. Because of the short lifespan of probiotics, this study was aimed at the evaluation of the contribution of nutrients in the improvement of growth and viability of the microorganism for the purpose of its further application in the formulation of whey-based beverages. A maximal cell growth of 8.70 log₁₀ cfu mL⁻¹ and viability of less than 5 days were achieved during the fermentation of whey supplemented with yeast extract (3.0%) and inulin (1.0%), including the synergistic effect of temperature 39 °C. Elimination of inulin from the fermentation process reduced the viable cell count by 0.2 log₁₀ cfu mL⁻¹, but the addition of 1.0% inulin after fermentation extended the viability of Lb. johnsonii NRRL B-2178 by 10 days.     

Effect of inulin on growth and bacteriocin production by Lactobacillus plantarum in stationary and shaken cultures

The prebiotic effect of inulin added to MRS medium on growth and bacteriocin production by L. plantarum ST16 Pa was investigated in stationary cultures in anaerobic jars with medium containing 0.025% sodium thioglycolate or in flasks shaken at 100 rpm. In the presence of 1% inulin in anaerobic stationary cultures, this strain produced lactic acid at a level that was 36.5% higher than in the absence of the polysaccharide. In shaken cultures without inulin, cell count was 54% higher than in the stationary ones. Under stationary conditions in anaerobic jars, the addition of inulin increased the maximum specific growth rate from 0.37 to 0.49 h^?1 and reduced the generation time from 1.85 h to 1.40 h. Consequently, the exponential phase was shortened from 12 to 9 h when the cells were grown in stationary cultures with the oxygen scavenger. Despite this effect of inulin on growth rate, stationary cultures without inulin displayed higher antimicrobial activity against Listeria monocytogenes L104 (3200 AU/mL) than cultures with inulin (1600 AU/mL); therefore, inulin behaved as a compound able to accelerate growth rather than to stimulate bacteriocin production. The results presented in this study are very promising, as L. monocytogenes is a well‐known foodborne pathogenic microorganism. Moreover, L. plantarum ST16 Pa has proven to be a potential producer of a natural food preservative at an industrial level.     

Simultaneous Determination of Caffeine and Aspartame in Diet Supplements and Non-Alcoholic Beverages Using Liquid-Chromatography Coupled to Corona CAD and UV-DAD Detectors

A method for the simultaneous determination of caffeine and aspartame in various diet supplements and non-alcoholic beverages is presented. The analytes were analysed by high-performance liquid chromatography coupled to a charged aerosol detector (Corona CAD) and ultraviolet-diode array detector (UV-DAD) simultaneously connected in series. The method was validated using a Thermo Hypersil Gold-C18 column packed with 5 μm shell particles (150 × 4.6 mm) and acetonitrile–water (15/85% v/v) mobile phase at a flow rate of 1.00 mL/min. The elaborated method was validated for linearity, precision and accuracy. The rapid HPLC–CAD–UV-DAD technique is suitable for quantifying caffeine and aspartame in the range of 0.25–75 μg/mL in diet supplements and non-alcoholic beverages. The limit of detection for caffeine and aspartame was 62 and 43 ng/mL for Corona CAD and 31 and 30 ng/mL for UV-DAD detector, respectively. Each analyte calibration curve had a correlation coefficient of at least 0.999 and was linear in the defined range. The accuracies of CAD and UV-DAD detection were all acceptable, with the mean value of 100% for aspartame and 98.3% for caffeine. Precision values ranged from 0.09% to 1.12%. The work has demonstrated that charged aerosol detector can be successfully used in a rapid screening technique for biologically active substances in non-alcoholic beverages and diet supplements.     

Viability of encapsulated Lactobacillus acidophilus (LA‐5) in UF cheese and its survival under in vitro simulated gastrointestinal conditions

In this study, the survival of Lactobacillus acidophilus (LA‐5) was monitored during storage for 60 days at (4 ± 1) °C and also under an in vitro gastrointestinal (GI) model. A significant increase in the number of LA‐5 was found subsequent to 30 days of storage but numbers were reduced following 60 days. While the survival of micro‐encapsulated Lactobacillus acidophilus (LA‐5) was enhanced during the storage and in vitro gastrointestinal simulation, the addition of inulin did not improve the viability of this micro‐organism. During the storage time, survival of L. acidophilus (LA‐5) remained up to 6 log (cfu/g) in the UF white cheese.     

Comparison of Properties of New Sources of Partially Purified Inulin to Those of Commercially Pure Chicory Inulin

Newly developed inulin powders were prepared from roots of Asparagus falcatus (AF) and Taraxacum javanicum (TJ) plants grown in Sri Lanka. Inulin content, analyzed by enzymatic spectrophotometric as well as high‐performance liquid chromatographic methods, showed that AF and TJ inulin powders contain 65.5% and 45.4% (dry wt) inulin, respectively, compared with 72% dry wt in the commercially available chicory inulin. Treating the AF and TJ inulin powders using ion exchange techniques significantly (P < 0.05) reduced their contents of micro (Zn, Cu, Mn, Fe) and macro (Na, K, Ca, Mg) elements. Enzymatic hydrolysis of inulin into fructose and glucose by fructanase, and FT‐IR analyses proved that the developed AF and TJ inulins have characteristic molecular composition similar to commercial inulin. TJ inulin contained significantly (P < 0.05) greater amounts of total phenolics (4.37 mg GAE/g), total flavonoids (2.79 mg QE/g), and antioxidant capacity (833.11 mM TE/g) than AF inulin, which contained 1.33 mg GAE/g of total phenolics, 0.43 mg QE/g of total flavonoids, and 406.26 mM TE/g antioxidant capacity. The current study suggests that the newly developed inulin from AF and TJ roots could be used as an alternative commercial source of inulin for the food industry.     

Storage stability of prebiotic fermented milk obtained from permeate resulting of the microfiltration process

The permeate, obtained from the best microfiltration process, was employed in the preparation of fermented milks, without inulin (control) and with 5 g 100 g^?1 inulin (prebiotic), stored at 5 ± 1 °C for 28 days. It could be verified that the storage period and addition of inulin increased the total solids and carbohydrate contents, the caloric value and the acidity, and decreased the pH. The addition of inulin resulted in a fermented product with a lower syneresis index, and greater firmness and cohesiveness. The inulin employed resulted in a product with a greater tendency toward a greenish coloration.     

Impact of inulin and okara on Lactobacillus acidophilus La-5 and Bifidobacterium animalis Bb-12 viability in a fermented soy product and probiotic survival under in vitro simulated gastrointestinal conditions

The effect of inulin and/or okara flour on Lactobacillus acidophilus La-5 and Bifidobacterium animalis Bb-12 viability in a fermented soy product (FSP) and on probiotic survival under in vitro simulated gastrointestinal conditions were investigated throughout 28 days of storage at 4 °C. Employing a 2² design, four FSP trials were produced from soymilk fermented with ABT-4 culture (La-5, Bb-12, and Streptococcus thermophilus): FSP (control); FSP-I (with inulin, 3 g/100 mL of soymilk); FSP-O (with okara, 5 g/100 mL); FSP-IO (with inulin + okara, ratio 3:5 g/100 mL). Probiotic viabilities ranged from 8 to 9 log cfu/g during the 28 days of storage, and inulin and/or okara flour did not affect the viability of La-5 and Bb-12. Bb-12 resistance to the artificial gastrointestinal juices was higher than for La-5, since the Bb-12 and La-5 populations decreased approximately 0.6 log cfu/g and 3.8 log cfu/g, respectively, throughout storage period. Even though the protective effect of inulin and/or okara flour on probiotic microorganisms was not significant, when compared to a fresh culture, the FSP matrix improved Bb-12 survival on day 1 of storage and may be considered a good vehicle for Bb-12 and could play an important role in probiotic protection against gastrointestinal juices.     

A simplified spectrophotometric method for the determination of inulin in Jerusalem artichoke (<Emphasis Type="Italic">Helianthus tuberosus</Emphasis> L.) tubers

A simple spectrophotometric method was developed for the analysis of inulin in Jerusalem artichoke tubers. The inulin was extracted from the artichoke tuber samples using accelerated solvent extraction method, before subsequent hydrolysis in acid condition. The hydrolysates were then analyzed for fructose using spectrophotometry. The spectrophotometric method is based on oxidation of fructose by periodate and evaluation of the remaining periodate by measuring the absorbance at 350 nm of the tri-iodide complex formed, upon addition of potassium iodide. The optimum conditions for the detection of fructose were 0.1 mmol L⁻¹ periodate and 1.5 mmol L⁻¹ potassium iodide at pH 6.0. The proposed method was validated for its analytical performance parameters including accuracy, precision, and recovery. The method was applied to the determination of inulin in ten varieties of Jerusalem artichoke grown in the northeastern part of Thailand. The inulin content in the samples was found to be in the range of 63–75.5% dry weight, and the degree of polymerization was in the range of 14–20. The inulin contents obtained from the proposed spectrophotometry were not significantly different (p = 0.05) from those obtained from high-performance anion-exchange chromatography coupled with pulsed amperometric detection. The results indicated that the present spectrophotometric method can be used as an alternative to chromatographic analysis for the determination of inulin in plant samples.     

Effects of cross-linked inulin with different polymerisation degrees on physicochemical and sensory properties of set-style yoghurt

This work investigated effects of cross-linked inulin with different degrees of polymerisation (DP, average = 7 and 15) on physicochemical and sensory properties of set-style yoghurt. Compared with set-style yoghurt made with native inulin (average DP = 4 and 11), yoghurts with cross-linked inulin had higher acidity and lower syneresis values, with a shelf-life of 14 days. Supplementation of cross-linked inulin with higher DP resulted in enhanced firmness and adhesiveness of yoghurts. In addition, bacterial counts showed that yoghurts with cross-linked inulin exhibited longer retention of Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus cell viability than that with native inulin. Sensory evaluation indicated that yoghurt with cross-linked long-chain inulin received higher scores for overall acceptability than other samples. However, different types of inulin did not significantly affect odour and colour of set-style yoghurt. Consequently, cross-linked inulin prepared can be exploited as a prebiotic to prolong shelf-life of yoghurt.     

Stability of microencapsulated lactic acid bacteria under acidic and bile juice conditions

The probiotic strains Lactobacillus brevis CCMA1284 and Lactobacillus plantarum CCMA0359 were microencapsulated by spray drying using different matrices – whey powder (W), whey powder with inulin (WI) and whey powder with maltodextrin (WM). Viability of the microencapsulated strains in acid and bile juices and during 90 days of storage (seven and 25 °C) was evaluated. The two strains exhibited high encapsulation efficiency (> 86%) by spray drying. The different matrices maintained L. plantarum viability above six log CFU g⁻¹ at 7 °C for 90 days, whereas similar results for L. brevis were observed only for W. The use of inulin as matrix of encapsulation did not enhance bacterial viability in the evaluated conditions. In general, the use of W and WM as matrices was effective for L. plantarum viability. However, only W was effective for L. brevis in the evaluated conditions. The spray drying technique was successfully adopted for the encapsulation of L. plantarum CCMA0359 and L. brevis CCMA1284 strains.     

Inulin-based emulsion-filled gel as a fat replacer in prebiotic- and PUFA-enriched dry fermented sausages

In order to produce fermented sausages with prebiotic fibre and improved fatty acid composition, 16% of pork back fat was replaced with inulin gelled suspension (I) and inulin linseed oil gelled emulsion (IO). Physico-chemical analysis, fatty acid profiles, lipid oxidation, microbiological, textural, colour and sensory analysis were carried out. The fat content was lower in I (31.38%) and IO (35.36%) modified sausages compared to control (44.37%) (P < 0.05). IO sausages had lower SFA and MUFA and higher PUFA content with an improved n-6/n-3 ratio (2.23) (P < 0.05) and α-linolenic acid increment (5.74 g per 100 g). Reformulation led to decrease in springiness, chewiness and hardness and increase in adhesiveness of the sausages. Modified sausages had lower L* and higher a* values, while b* values of I sausages did not differ compared to control sausages. Modified sausages were acceptable regarding all sensory attributes. Lipid oxidation parameters showed higher susceptibility to oxidation and lipolysis in IO sausages.     

Rheological properties and structure of inulin–whey protein gels

The rheological properties, structure and synergistic interactions of whey proteins (1–7%) and inulin (20% and 35%) were studied. Gelation of whey proteins was induced with Na⁺. Inulin was dissolved in preheated whey protein solutions (80 °C, 30 min). Inulin gel formation was strongly affected by whey proteins. The presence of whey proteins at a level allowing for protein gel network formation (7%) significantly increased the G′ and G″ values of the gels. Scanning electron micrographs showed a thick structure for the mixed gel. Whey proteins at low concentrations (1–4%) were not able to form a gel; further, these low concentrations partly or wholly impaired formation of a firm inulin gel. Although interactions between inulin and whey proteins may be concluded from hydrophobicity measurements, the use of an electrophoretic technique did not show any inulin–whey protein complexes.     

Optimisation of inulin extraction from globe artichoke (Cynara cardunculus L. subsp. scolymus (L.) Hegi.) by electromagnetic induction heating process

In this study, a D‐optimal design was used to optimise the extraction process conditions of inulin with a high degree of polymerisation from Globe artichoke heart (Cynara cardunculus L. subsp. scolymus (L.) Hegi.), using electromagnetic induction heating (EMIH) as a new extraction process. Four factors were simultaneously studied which were the extraction temperature (55–90 °C), the extraction time (30–120 min), the weight ratio (plant material dry weight/volume of distilled water: 5–10%) and the mode of heating (conventional or electromagnetic induction heating). It was found that the second‐order polynomial models developed by the response surface methodology (RSM) describe adequately the relationship between the factors and responses (extraction yield, viscosity and solubility of inulin). The optimum extraction conditions that led to a maximal extraction yield (45.98%) and an optimal viscosity (3.25 mL g^?1) of extracted inulin are temperature of 89.49 °C, extraction time of 120 min and a 5.01% of weight ratio using EIMH process. Fourier Transform InfraRed spectroscopy spectrum of the extracted inulin was identical to that of the native inulin. The analysis of the extract by thin‐layer chromatography confirms the absence of pectin in the final product, as well as the X‐ray diffraction analysis exhibits a semi‐crystalline structure of the biopolymer.     

Effect of chlorophyll removal and particle size upon the nutritional and technological properties of powdered by‐products from artichoke (Cynara scolymus,L.) industrial canning

In this study, the effect of the particle‐size fractionation (Ø < 0.212 mm and 0.212 mm < Ø < 0.991 mm) and chlorophyll extraction on the nutritional and technological properties of the powdered artichoke ingredient was evaluated. The contents of minerals, protein, fat, carbohydrates and dietary fibre together with the content in bioactive compounds such as inulin and phenolics were determined. Other properties such as water‐ and oil‐holding capacities, water activity and antioxidant capacity were measured. The ingredient with chlorophyll and the lowest particle size presented the highest phenolic content and antioxidant capacity (8.4 mg of vitamin C equivalents per 100 g of dry matter) and water‐ and oil‐holding capacities. The removal of chlorophyll increased the oil‐holding capacity (from 59.7% to 94.6%), which was much higher than in the coarse ingredient (34%), but has a deleterious effect reducing the antioxidant capacity and the inulin content. The ingredients also showed high dietary fibre (22.5–33%), inulin (9–16%) and mineral (7.5–7.8%) contents. Although the ingredient with chlorophyll and smaller particle size had the higher antioxidant capacity, the removal of chlorophyll improved the technological properties to be used as food ingredient without affecting significantly to the nutritional value.     

The effect of co-encapsulation of Lactobacillus rhamnosus GG ATCC 53103 with inulin on alginate/chitosan matrix: the viability in fermented soy blend and simulated digestive system

This research verified the ability of Lactobacillus rhamnosus encapsulated with inulin to tolerate the simulated digestive system and their viability in a soy blend. Probiotic encapsulated in alginate-chitosan matrix without inulin presented a better encapsulation efficiency (80.92%) than encapsulation with inulin (57.39%). On the 28th day, the count of probiotics decreased by 3.42 and 1.99 logarithmic cycles of free and encapsulated cells without inulin, respectively. In contrast, the microorganisms encapsulated with inulin showed an increase of 1.26 logs CFU g⁻¹. During gastrointestinal simulation, cell counts decreased by 0.78, 1.55 and 1.95 CFU g⁻¹ logs for encapsulated cells without inulin, free and encapsulated with inulin, respectively. Sensory panellists liked the fermented soy blend with encapsulated lactobacilli, and this result shows the possibility to create new probiotic foods of plant origin. Therefore, the alginate/chitosan matrix can be considered adequate for the encapsulation of L. rhamnosus. The inulin reduces the encapsulation efficiency and increases the cell loss in gastrointestinal simulation. Considering cellular losses, the best option for preparing a fermented soy blend is to use L. rhamnosus encapsulated without inulin.     

Rheological properties of reduced-fat and low-fat ice cream containing whey protein isolate and inulin

Instrumental analyses were used to evaluate the rheological properties of regular (10%), reduced-fat (6%) and low-fat (3%) ice cream mixes and frozen ice creams stored at −18 °C. The reduced-fat and low-fat ice creams were prepared using 4% whey protein isolate (WPI) or 4% inulin as the fat replacement ingredient. The composition, colour, apparent viscosity, consistency coefficient, flow behaviour index, hardness and melting characteristics were measured. No effect of WPI or inulin was obtained on the colour values. Compared with regular ice cream, WPI changed rheological properties, resulting in significantly higher apparent viscosities, consistency indices and greater deviations from Newtonian flow. In addition, both hardness and melting resistance significantly increased by using WPI in reduced-fat and low-fat ice creams. Inulin also increased the hardness in comparison to regular ice cream, but the products made with inulin melted significantly faster than the other samples.     

Inulin and maltodextrin can replace fat in baked savoury legume snacks

A baked yellow split pea cracker was developed with fat replacement (0%, 25%, 50%, 75% and 100%) using inulin, hydroxypropyl methylcellulose and maltodextrin. Effects of fat replacement on physical (water activity, moisture content, colour and hardness), nutritional properties and consumer acceptance (nine‐point hedonic rating) of snacks were investigated. Water activity (0.15–0.32) and moisture (1.28–3.16%) readings were consistent, and products were considered shelf stable. High levels of fat replacement (100%) were detrimental to snack colour and hardness. Snacks with 75% fat replacement using inulin and maltodextrin received similar mean overall acceptability scores (6.40 ± 1.36 and 6.26 ± 1.37, respectively) to the control and a similar commercial product. These snacks were eligible to claim that they were a ‘good source’ of protein (requirement; ≥10 g per serve) and an ‘excellent source’ of dietary fibre (requirement; ≥7 g per serve) while providing ‘reduced’ fat content (≤25% than reference food) based on the Australian Food Standards Code.