Influence of cocoa products on rheological, fatty acid profile and quality characteristics of biscuits.

Cocoa products namely cocoa powder (CP), cocoa butter (CB) and cocoa mass (CM) were selected for their utilization in soft dough biscuits. CP was blended with the refined wheat flour (WF-0, 5, 10 and 15% levels) and rheological and quality characteristics of biscuits were studied. The spread ratio decreased (10.1-8.8), density (0.49-0.52 g/cm3) and breaking strength values (1127-1369 g force) increased gradually with increase in CP. Combination of GMS and SSL at 0.25% each improved the quality of biscuits at 10% incorporation of CP. Further the biscuit fat (BF) was replaced with CB (0, 25, 50 and 75%). Later the biscuits with CM were prepared by replacing the flour (15%) and BF (0, 25, 50 and 75%). Acceptability of the CM based biscuits was better when compared to CB based biscuits. The total polyphenol content in control biscuits was 55.55 mg/100 g and was in the range between 81.98 and 102.05 mg/100 g for cocoa based biscuits. The protein content in cocoa based biscuits was marginally higher than the control biscuit. Though there was a wide variation in the fat content and different fatty acids in raw materials, interestingly, the values varied narrowly in biscuits.

Enrichment of Cookies with Fruits and Their By-Products: Chemical Composition, Antioxidant Properties, and Sensory Changes.

Cookies made from wheat have become increasingly popular as a snack due to their various advantages, such as their convenience as a ready-to-eat and easily storable food item, wide availability in different types, and affordability. Especially in recent years, there has been a trend towards enriching food with fruit additives, which increase the health-promoting properties of the products. The aim of this study was to examine current trends in fortifying cookies with fruits and their byproducts, with a particular focus on the changes in chemical composition, antioxidant properties, and sensory attributes. As indicated by the results of studies, the incorporation of powdered fruits and fruit byproducts into cookies helps to increase their fiber and mineral content. Most importantly, it significantly enhances the nutraceutical potential of the products by adding phenolic compounds with high antioxidant capacity. Enriching shortbread cookies is a challenge for both researchers and producers because the type of fruit additive and level of substitution can diversely affect sensory attributes of cookies such as color, texture, flavor, and taste, which have an impact on consumer acceptability.

Bioaccessibility of Phenolic Acids and Flavonoids from Buckwheat Biscuits Prepared from Flours Fermented by Lactic Acid Bacteria.

The literature reports that the consumption of common buckwheat (Fagopyrum esculentum Moench), exactly the polyphenols it contains, is associated with a wide spectrum of health benefits. Therefore, the determination of the bioaccessibility of phenolic acids and flavonoids from buckwheat biscuits formulated from liquid-state fermented flours (BBF) by selected lactic acid bacteria (LAB) after gastrointestinal digestion was addressed in this study. Bioaccessibility could be defined as the fraction of a compound that is released from the food matrix in the gastrointestinal lumen and used for intestinal absorption. The bioaccessibility of eight phenolic acids (protocatechuic, vanillic, syringic ferulic, caffeic, sinapic, p-coumaric, and t-cinnamic) and six flavonoids (epicatechin, vitexin, orientin, apigenin, kaempferol, and luteolin) were provided for BBF and BBC (buckwheat biscuits prepared from fermented and unfermented flours, respectively). The bioaccessibility indexes (BI) indicated the high bioaccessibility of phenolic acids and improved bioaccessibility of flavonoids from BBF. Moreover, the data provide evidence for the suitability of selected LAB strains to be used as natural sour agents for further bakery product development rich in phenolic acids and flavonoids with LAB-dependent bioaccessibility.

Study on the Incorporation of Oat and Yeast ß-Glucan into Shortbread Biscuits as a Basis for Designing Healthier and High Quality Food Products.

According to international health and food organizations and authorities, people should limit fat intake since fat is the most caloric component of food and it is often a source of unsafe saturated fatty acids (FA) and trans isomers. The greatest health benefits come from replacing shorts with dietary fiber molecules. The aim of the study was to determine the possibility of reducing shortening content, which has an undesirable profile of FA, by addition of ß-glucan molecules in shortbread biscuits. The effect of oat and yeast ß-glucan supplementation on physical and sensory quality of products with reduced fat content (max 15%) were studied. It was shown that the substitution of shortening by ß-glucan in shortbread biscuits is possible to a limited extent. Reduction in product energy value (up to 36 kcal/100 g) and content of undesirable FA (maximum 2.1 g/100 g) and increased of ß-glucan content, regardless of the type, caused deterioration of biscuits quality and affected changes during storage. The substitution of shortening by ß-glucan in food is a good way to improve nutritional value by increasing the amount of dietary fiber molecules, reducing calories, and amount of SFA in diets.

Designing Nutritious and Sustainable Biscuits Using Upcycled Fibre-Rich Ingredients Obtained by Hot Air - Microwave Drying of Orange by-Products.

Circular use of resources implies developing mild processes to transform food by-products into value-added products, without using organic solvents or extensive washing and drying steps. Refined ingredients are commonly used in gluten-free bakery resulting in high levels of saturated fatty acids and sugars as well as a lack of essential nutrients like dietary fibres. The objective of this study was (i) to compare the nutritional composition and the water retention capacity (WRC) of an upcycled orange fibre dried by hot air combined with microwave (HAD+MW) and a commercial orange fibre obtained by different methods (COM), and (ii) to compare the nutritional, texture and sensory profile of gluten-free biscuits formulated with HAD+MW and with COM fibres. The total dietary fibre content (72.0 ± 3.0%) and WRC (21.1 ± 2.7 gwater/ g) of HAD+MW fibre did not differ from the nutritional composition of the control orange fibre (COM). However, for HAD+MW fibre, protein (+2.34 fold), fat (-4.75 fold), ash (-2.31 fold), sugars (-1.42 fold) and moisture content (+11.5 fold) was different from COM. Instrumental texture analysis showed that biscuits with HAD+MW fiber resulted in less hardness (26%) than those with COM fiber. However, this difference was not perceived by panellists (p > 0.05). Exterior colour, cereal, vanilla and citrus aroma-flavour, and granularity were slightly more intense in HAD+MW biscuits but still similar to the commercial control fiber. Thus, the HAD+MW drying method can be used for upcycling orange by-products, obtaining less refined and more nutritious and sustainable ingredients for fiber-enrichment of gluten-free biscuits.

Nɛ-(carboxymethyl)lysine, Available Lysine, and Volatile Compound Profile of Biscuits Enriched with Grape by-Product During Storage.

We investigated the changes in Nɛ-(carboxymethyl)lysine (CML) and available lysine content, antioxidant properties, volatiles, and oxidation products of biscuits enriched with grape by-product (GP), stored for six months under a modified atmosphere of 0%/30%/70% O2/CO2/N2 and in air. Fresh GP-formulated biscuits showed lower concentrations of CML (89%), available lysine (40%), and pyrazines (75%), but higher antioxidant capacities (~ sixfold), furans (12-fold), and lipid-derived compounds (three-fold) than the control. Although ~ 15% higher losses of Maillard-type volatiles were identified in the air atmosphere during storage, lipid oxidation was ~ 30% less pronounced in the modified atmosphere. A significant correlation of 0.994 between the reduction in CML and the available lysine suggest further CML reactions with the ɛ-NH2 group of amino acids. Significant correlations (of -0.550 to -0.980) between oxidation products, antioxidant capacities, and changes in CML content during storage suggest that these parameters might be involved in the CML elimination mechanism.

Development of biscuits supplemented with papaya seed and peel: effects on physicochemical properties, bioactive compounds, in vitro absorption capacities and starch digestibility.

In this study, wheat biscuits were prepared by supplementing with papaya seed (PS) and papaya peel (PP) in range of 2 to 10%. As compared to control (un-supplemented) samples, PS and PP-supplemented biscuits were analyzed for their physicochemical properties, bioactive compounds, antioxidant activities, in vitro absorption capacities, starch digestibility and sensory attributes. As compared to PS, PP had lower energy value, higher bioactive compounds and antioxidant activity along with better in vitro adsorption capacities. Overall, PS and PP addition from 2 to 10% significantly improved nutritional components, polyphenol compounds, antioxidant activities, and caused marked rises in NO2 - ion, cholesterol and bile acid absorption capacities of supplemented biscuits. Moreover, PS and PP-addition showed significant concentration-dependent decreases in glucose release response during various in vitro starch digestion intervals. Based on sensory characteristics, biscuits supplemented up to 4% PS and PP showed excellent overall acceptability, however, in comparison with PS, 4% PP-supplemented biscuits exhibited the better sensory properties. Therefore, PP-supplemented biscuits up to 4% could be utilized as a convenience food. Moreover, PS and PP-supplementation of wheat biscuits led to improvement of functional properties as a valuable source of bioactive compounds and high radical-scavenging activities.

In Vitro Bioaccessibility of Bioactive Compounds from Citrus Pomaces and Orange Pomace Biscuits.

The present investigation aimed to provide novel information on the chemical composition and in vitro bioaccessibility of bioactive compounds from raw citrus pomaces (mandarin varieties Clemenule and Ortanique and orange varieties Navel and Valencia). The effects of the baking process on their bioaccessibility was also assessed. Samples of pomaces and biscuits containing them as an ingredient were digested, mimicking the human enzymatic oral gastrointestinal digestion process, and the composition of the digests were analyzed. UHPLC-MS/MS results of the citrus pomaces flavonoid composition showed nobiletin, hesperidin/neohesperidin, tangeretin, heptamethoxyflavone, tetramethylscutellarein, and naringin/narirutin. The analysis of the digests indicated the bioaccessibility of compounds possessing antioxidant [6.6-11.0 mg GAE/g digest, 65.5-97.1 µmol Trolox Equivalents (TE)/g digest, and 135.5-214.8 µmol TE/g digest for total phenol content (TPC), ABTS, and ORAC-FL methods, respectively; significant reduction (p < 0.05) in Reactive Oxygen Species (ROS) formation under tert-butyl hydroperoxide (1 mM)-induced conditions in IEC-6 and CCD-18Co cells when pre-treated with concentrations 5-25 µg/mL of the digests], anti-inflammatory [significant reduction (p < 0.05) in nitric oxide (NO) production in lipopolysaccharide (LPS)-induced RAW264.7 macrophages], and antidiabetic (IC50 3.97-11.42 mg/mL and 58.04-105.68 mg/mL for α-glucosidase and α-amylase inhibition capacities) properties in the citrus pomaces under study. In addition, orange pomace biscuits with the nutrition claims "no-added sugars" and "source of fiber", as well as those with good sensory quality (6.9-6.7, scale 1-9) and potential health promoting properties, were obtained. In conclusion, the results supported the feasibility of citrus pomace as a natural sustainable source of health-promoting compounds such as flavonoids. Unfractionated orange pomace may be employed as a functional food ingredient for reducing the risk of pathophysiological processes linked to oxidative stress, inflammation, and carbohydrate metabolism, such as diabetes, among others.

Influence of Chia Seed, Buckwheat and Chestnut Flour Addition on the Overall Quality and Shelf Life of the Gluten-Free Biscuits.

RESEARCH BACKGROUND: In spite of being a significantly growing segment, there are still problems regarding the nutritional, technological and sensory profiles of gluten-free products. Thus, the combination of a variety of functional ingredients is required in order to achieve the desired product quality. EXPERIMENTAL APPROACH: Three types of flour, chestnut, buckwheat and potato, were chosen in this study because they are all gluten-free, nutritionally richer and technologically more advantageous than wheat flour. They are combined with chia seeds, which are also functional ingredients as they are rich in dietary fibre and unsaturated fatty acids. Therefore, this study aims to evaluate the utilization of chia seeds with chestnut, buckwheat and potato flour in biscuits as overall quality enhancers in gluten-free products. The proximate composition, total phenolic content, antioxidant activity, some biscuit quality parameters and the sensory properties of the samples were investigated, and some changes in these products during storage were monitored and evaluated. RESULTS AND CONCLUSIONS: According to the results, biscuits with chestnut flour had the highest phenolic content (400.2 mg gallic acid equivalent (GAE) per 100 g dry sample) and total antioxidant activity (155.5 mg Trolox equivalent (TE) per 100 g dry sample). Biscuits with chestnut and chia seeds had the hardness of 30.1 N (p<0.05). In addition, the use of chia seeds significantly increased the overall acceptability and flavour scores according to the sensory analysis results. During storage, chia seeds affected the oxidation stability; however, the fatty acid profile remained almost unchanged, except for the losses in lauric, stearic and α-linolenic acids (p<0.05). In conclusion, the biscuits with chestnut and chia seeds were more attractive than those made with other types of flour, with remarkably better nutritional characteristics and sensory attributes. NOVELTY AND SCIENTIFIC CONTRIBUTION: The study fulfils a need for the growing gluten-free market by combining together the functional nutrients of chia seeds, chestnut flour and buckwheat flour to achieve the nutritionally improved and organoleptically acceptable gluten-free biscuits. Furthermore, this study makes an overall evaluation of the changes in product quality during storage to provide new ideas for an overall innovation in the gluten-free food market.

Fatty Acids, Volatile and Sensory Profile of Multigrain Biscuits Enriched with Spent Malt Rootles.

Spent malt rootlets, a by-product of the brewing industry, are a rich source of protein, essential amino acids, healthy fats, polyphenols and minerals, and could be a new promising type of raw material from the nutritional, economic, sensory, and technical perspectives. However, their specific aroma profile could limit their addition in baked products. The aim of this work was to study the effect of spent malt rootlets addition on volatile derivatives of enriched biscuits in relation to their sensory profile. For this purpose, spent malt rootlets and enriched biscuits (0-25% spent malt rootlets added) were analyzed by GC-MS techniques, in order to obtain their fatty acids methyl esters and volatile compounds profile, while for the sensory analysis a nine-point hedonic score test was used. The results of this study reveal the fatty acids and volatile profile of spent malt rootlets and of the enriched biscuits with spent malt rootlets pointing out the contribution of fatty acids to the generation of aroma compounds. The influence of different aroma compounds on the consumer's preferences was studied and the optimum level addition of spent malt rootlets in multigrain biscuits was found to be 15%.

Nutritional, Physiochemical, and Antioxidative Characteristics of Shortcake Biscuits Enriched with Tenebrio molitor Flour.

Edible insects, due to their high nutritional value, are a good choice for traditional food supplementation. The effects of partial replacement of wheat flour and butter with mealworm flour (Tenebrio molitor) on the quality attributes of shortcake biscuits were studied. The approximate composition was analyzed, along with the physical properties and color. Moreover, the antioxidant properties, starch digestibility, and glycemic index were determined in vitro. The protein and ash contents in biscuits supplemented with mealworm flour increased, while the carbohydrates content decreased. The increasing insect flour substitution decreased the lightness (L*) and yellowness (b*) but increased the redness (a*), total color difference (ΔE), and browning index (BI). The spread factor for the sample with the highest proportion of mealworm flour was significantly higher than the other biscuits. Furthermore, higher additions of mealworm flour increased the antioxidant activity of the biscuits and contributed to an increase in the content of slowly digested starch, with a decrease in the content of rapidly digested starch. Therefore, the results of the research are promising and indicate the possibility of using edible insects to enrich food by increasing the nutritional and health-promoting values.

Effect of high-oleic rapeseed oil oleogels on the quality of short-dough biscuits and fat migration.

Short-dough biscuits are popular snacks. Unfortunately, fat used in most of these products has low nutritional value due to the high content of saturated fatty acids. The most popular fat used in bakery products is palm oil. In this work high-oleic rapeseed oil was used in the form of oleogels structured by waxes (canelilla, rice bran, yellow and white beeswax), monoacyloglicerols and ethylcelullose. In this form oil keeps nutritional value and has solid consistency. Obtained oleogels were significantly different than palm oil in terms of texture and viscosity. However, using oleogel with 5% of monoacylglicerols, as a shortening let to obtain biscuits with similar properties to control sample (with palm oil). Addition of 2 and 3% of candelilla wax, 8% of ethylcelullose, 2% of rice bran wax and 5% of monoacylglicerols allowed to get products from which lipid fraction migration was similar or smaller then from control sample.

Nutritional composition, physical characteristics, and sensory attributes of wheat based biscuits enriched with bullet pear (Canarium schweinfurthii) fruit pulp.

Fat is a major and important component of biscuits. The effect of substituting hydrogenated fat (HF) with bullet pear fruit pulp (BPFP) on quality characteristic of wheat biscuit was investigated. The pulp was prepared by soaking the fruit in warm water (65 °C) for 30 min, the black coat was scraped out and the pulp used in substituting HF at 0, 25, 50, 75 and 100% levels. Samples were analysed for physicochemical and sensory qualities. The result showed that moisture (5.68-7.0%), proteins (6.91-7.64%), crude fibre (0.47-0.84%) and ash contents (0.80-2.52%) increased (p < 0.05) with increase in BPFP substitution while 100% HF had highest (p < 0.05) score for fat (11.00%) and carbohydrate (76.39%). Result showed that weight (7.72-11.70 g), thickness (0.62-0.99 cm) and width (9.02-11.23 mm) of the biscuit samples significantly increased while spreading ratio and breakability decreased (p < 0.05) with BPFP substitution. Bullet pear pulp substituted biscuits had higher (p < 0.05) range value for vitamin C (2.36-13.15 mg/100 g) and vitamin E (4.07-8.78 mg/100 g). The minerals increased (p < 0.05) with increase in BPFP substitution and ranged from 8.54 to 18.13 mg/100 g (calcium), 6.46 to 25.68 mg/100 g (magnesium), 28.39 to 64.33 mg/100 g (phosphorus), 10.95 to 59.57 mg/100 g (potassium), 1.66 to 8.47 mg/100 g (iron) and 15.50 to 50.12 mg/100 g (sodium). The sensory results showed that 50% substitution of HF with BPFP had no significant difference (p > 0.05) from 100% HF biscuit in all parameters except for taste. Also all the samples were generally accepted by the panellist.

The Rate of Glucose Appearance Is Related to Postprandial Glucose and Insulin Responses in Adults: A Systematic Review and Meta-analysis of Stable Isotope Studies.

BACKGROUND: It is often assumed that lower postprandial glucose (PPG) and insulin (PPI) responses are induced by slower glucose influx from the gut (e.g., by delayed carbohydrate digestion). However, changes in the rate of appearance of glucose in the peripheral circulation [rate of appearance of exogenous glucose (RaE)] may be accompanied by changes in endogenous glucose production (EGP) and the rate of disappearance of total glucose into tissues (RdT). The quantitative relationships between reductions in RaE and PPG/PPI levels are unclear. OBJECTIVES: The objective was to perform a meta-analysis to quantify the effect of changes in RaE on changes in PPG and PPI levels (primary) and EGP and RdT (secondary). METHODS: We systematically searched the Scopus, Medline, and Cochrane library databases through 10 January 2019 for randomized, controlled, carbohydrate-rich interventions that aimed to reduce RaE in humans, measured using dual or triple stable isotope methods. The 2-h net incremental AUCs for all variables were extracted or calculated. Relationships between RaE and outcomes were quantified by weighted regression analyses. RESULTS: There were 12 articles, including 17 comparisons, that satisfied the inclusion criteria. The subjects were mainly men (60%), with age and BMI ranges of 18-40 y and 20.0-27.5 kg/m2, respectively. A 10% reduction in RaE was associated with reductions in PPG levels, PPI levels, and the RdT of 7% (95% CI: 2%, 12%; P = 0.010), 8% (95% CI: 2%, 13%; P = 0.012), and 11% (95% CI: 4%, 17%; P = 0.005), respectively, but was not significantly associated with a change in EGP (13%; 95% CI: -7%, 33%; P = 0.176). All fluxes together explained 70% and 26% of the variances in PPG and PPI levels, respectively. CONCLUSIONS: In adults, reducing glucose RaE by diet is associated with significant reductions in PPG levels, PPI levels, and the rate of glucose disposal. This trial was registered in the PROSPERO database with identifier CRD42018084824.

Determination of cadmium in bread and biscuit samples using ultrasound-assisted temperature-controlled ionic liquid microextraction.

BACKGROUND: In the present work, a simple and rapid method was proposed for the preconcentration of cadmium using ultrasound-assisted temperature-controlled ionic liquid microextraction (TC-IL-LPME). The dispersion of the ionic liquid (1-Hmim[PF6 ]) in the aqueous phase was performed by heating it in an ultrasonic bath, followed by cooling in an ice bath. After centrifugation, the enriched phase was dissolved in 45% (w/w) nitric acid solution to reduce viscosity, and the cadmium content was measured employing electrothermal atomic absorption spectrometry (ET-AAS). The 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol reagent (Br-PADAP) was used as a complexing agent. RESULTS: Under optimized conditions, the method had a detection limit of 2.0 ng L-1 and an enrichment factor of 24. The accuracy of the method was evaluated through the analysis of the certified reference material of brown bread (BCR-191). The method was applied to the determination of cadmium in samples of bread and biscuit. The limit of detection of the solid samples was 0.10 µg kg-1 . The recovery of cadmium in the samples varied between 93% and 107%. CONCLUSION: The proposed method is presented as a simple, cheap, ecological and a sensitive alternative for the determination of cadmium in bread and biscuit samples. © 2019 Society of Chemical Industry.

Glycemic Response in Diabetic Subjects to Biscuits Produced from Blends of Pigeon Pea and Wheat Flour.

This study evaluated the glycemic response to pigeon pea (PP) - wheat flour (WF) composite biscuits by diabetic patients. Biscuits were produced from flour made from the mixture of WF and PP flour in the proportion of 100:0 (100 - PP), 75:25 (75-PP), 50:50 (50-PP), 25:75 (25-PP), and 0:100 (WF), 4.5% ginger was used as flavor. Sensory evaluation revealed that 100-PP (6.54 ± 0.05) had highest acceptability and palatability attributes (p < 0.05). Glycemic index (GI) and glycemic load (GL) of the biscuits ranged from 100 - PP (41.36 ± 0.30) to CAB (79.89 ± 1.00) and 100-PP (10.57 ± 0.01) to CAB (30.70 ± 0.40), respectively. All the composite biscuits had low GI < 60 and GL < 20. Composite biscuit may suggest a cheap, adequate and safe supplementary diet for diabetic patients.

Chemical and physical changes during storage of differently packed biscuits formulated with sunflower oil.

Various innovative materials are already present on the market, but there is scarce knowledge on their performances when used in real food system. In this study, two innovative packaging materials were investigated for the evaluation during storage of biscuits formulated with sunflower oil and compared to a traditional one. To this aim, three different flexible and composite film containing a metalized plastic layer and a paper layer were used. The control included orientated polypropylene (OPP), while the innovative materials contained poly-lactic acid or OPP with a pro-oxidant additive, ethylene vinyl acetate. The physical (moisture, water activity, hardness/crispness) and chemical (peroxide value, conjugated dienes and trienes, and hexanal and nonanal formation) changes of biscuits were monitored during accelerated storage (35 °C and 50% of relative humidity for 105 days). Packaging materials did not have significant impact on textural quality of biscuits. Instead remarkable differences were observed during storage in the evolution of different lipid oxidation compounds, moisture content and water activity among differently packed biscuits. A new ecofriendly packaging showed the best performances in terms of physico-chemical quality of biscuits. The obtained results provide useful information for industrial application.

Preparation of Doum fruit (Hyphaene thebaica) dietary fiber supplemented biscuits: influence on dough characteristics, biscuits quality, nutritional profile and antioxidant properties.

The increasing demand for functional foods has boosted up the food industry to produce fiber-enriched products. In this study, dietary fiber (DF) was isolated from Doum fruit by exploiting the combination of microwave reactor technique and superfine grinding technology. The isolated Doum dietary fiber (DDF) possessed a high content of total dietary fiber, essential minerals and total polyphenols with good antioxidant activity. Biscuits were prepared by substituting wheat flour with DDF at different levels (0, 2.5, 5, 7.5 and 10%) and assessed for dough mixing properties and biscuit quality. The results showed that an increase of DDF in the flour affected physical parameters of biscuits by increasing the biscuits hardness and reducing the diameter, thickness and spread ratio. Supplementation of biscuits with DDF improved the nutritional value in terms of DF contents and essential minerals. Improvement in total phenolic contents (TPC) and antioxidant activities of the biscuits were also noted as a result of DDF supplementation. Biscuits supplemented with 7.5% DDF showed overall better sensorial characteristics. Conclusively, this study has shown that supplementation of wheat flour with DDF improved nutritional profile, antioxidant properties and overall consumer acceptability of biscuits. The present findings will be helpful regarding the development of functional foods enriched with DDF.

Changes on physicochemical and rheological properties of biscuits substituted with the peel and alcohol-insoluble solids (AIS) from cactus pear (Opuntia ficus-indica).

Cactus pear fruit consists of the peel, seeds and pulp. The peel is a major waste in cactus pear pulp based products accounting about 37.72% of the fruit weight. The aim of this study was to utilized and characterized the physicochemical and rheological properties of biscuits substituted with extracted cactus pear peel (CPP) and alcohol-insoluble solids (AIS) from cactus pear (Opuntia ficus-indica). To prepare AIS, peels were shredded and dropped in ethanol (70%) for 15 min. The mixture was boiled at 70 °C for 30 min, filtered and washed with ethanol 70% and the washing repeated until no sugars. The residue was washed and dried at room temperature. Changes in physiochemical and rheological properties of extracted CPP and AIS from cactus pear to qualify determine their use in the production of them to produce a fiber-rich food product. The water-holding capacity was 3.7 ml/g for the peel and 1.5 ml/g for the AIS, and the oil-holding capacity was approximately the same for both the CPP and AIS. The protein content was 3.5% for the CPP and 3.72% for the AIS. The CPP and AIS contained little fat (1.22% and 1.44%, respectively). Potassium and calcium in the AIS had the highest concentration, at 21.49 g/kg and 44.04 g/kg, respectively, and these minerals were found at 22.07 g/kg and 16.66 g/kg, respectively, in the CPP. The dominant phenolic compounds found in the CPP were pyrogallol, catechol, catechin, and alpha-coumaric acid. The results showed that the AIS contained pyrogallol (61.67 ppm), benzoic acid (10.68 ppm), vanillic acid (7.66 ppm), catechin (4.65 ppm) and salicylic acid (4.51 ppm). The CPP was rich in glucose (25.95%) and fructose (21.36%) compared to the AIS. The sensory evaluation indicated that 7.5% dried cactus pear peel or 7.5% AIS can be successfully used in substitution of wheat flour biscuits. It could be conducted cactus pear as major by-product can be important for the industrial utilization.

Sensory and physicochemical changes in gluten-free oat biscuits stored under different packaging and light conditions.

The influence of different packaging films and their thickness (polyethylene terephthalate/casting polypropylene (PET/CPP_34), biaxially oriented polypropylene (BOPP_40), polyvinylchloride (PVC_12), BOPP/CPP_50 and polyethylene/ethylene vinyl alcohol/polypropylene (PE/EVOH/PP_50) on the quality of gluten-free oat biscuits was evaluated for a storage period up to 3 months under light and darkness conditions. Periodically (day 30, 60 and 90), physical parameters, peroxide value, texture and microbiological parameters together with sensory attributes (surface colour, smell, taste, crunchiness and off-flavour) were assessed. Moisture and water activity of biscuits decreased during storage in all packages. The highest peroxide value was obtained for biscuits packed in PVC_12, while the lowest was for the PE/EVOH/PP_50, for both storage conditions. The biscuits' colour changed from yellow-brown to light yellow and the change was more pronounced in the light as compared to the dark storage conditions. The hardness value decreased (p > 0.05) during the storage period. The electronic nose system showed that the distinct volatile composition of the biscuits stored in the light was correlated with the higher scores of the off-flavour attribute and with the peroxide values. The sensory data showed that BOPP/CPP_50 preserved the colour of the biscuits, while PE/EVOH/PP_50 kept the initial crunchiness of the biscuits up to 90 days of storage in both light and dark conditions. The study suggested that BOPP/CPP_50 and PE/EVOH/PP_50 can be used for gluten-free oat biscuits' packaging and storage up to 90 days for both conditions studied, without adversely affecting their physicochemical and sensory properties.