Development of biscuits using purple rice flour, defatted green-lipped mussel powder and spices

Biscuits are the most popular bakery food consumed worldwide. The nutritional values of biscuits can be fortified by adjusting their formulations. Wheat flour is one of the main ingredients in a biscuit mix and biscuits can be fortified by using alternative flours containing a high nutritional value, such as Thai purple rice (Oryza sativa L.) flour. However, this has seldom been used in bakery products, i.e. bread or biscuits. Defatted green-lipped mussel powder (Perna canaliculus) is a by-product, which is a good source of protein to add to biscuits. Spices tend to give the biscuits a nice smell and taste, particularly in biscuits where defatted green-lipped mussel powder (P. canaliculus) has been added to the recipe to increase the protein content. Wheat-purple rice biscuits (50:50) supplemented with defatted mussel powder at 0-20%, together with spices, were evaluated by measuring their proximate compositions, physical characteristics and antioxidant contents along with their liking scores as derived from a standard tasting trial. This study was carried out in 5 stages: 1) substituting a portion of wheat flour with Thai purple rice flour, 2) producing biscuits from different flour mixtures, 3) incorporating defatted mussel powder to the biscuits containing purple rice flour, 4) using spices in the formulation of biscuits with defatted mussel powder, 5) studying changes in the quality of biscuits containing defatted mussel powder and spices during storage for four months. An increase in substitution levels of purple rice flour increased the level of dietary fibre from 2.3 to 5.6% and protein digestibility from 24.8 to 66.46%, and decreased the predicted glycaemic index (pGI) from 63.1 to 48.6 compared to refined wheat flour. Lower amounts of rapidly digested starch with higher slowly digested starch contents were found in whole flour made from purple rice with a 75% substitution of purple rice flour for wheat flour. In addition, antioxidant compounds (total phenolic compounds, anthocyanin and total flavonoid) and antioxidant activity significantly increased (P < 0.05) in the substituted flour compared to the refined wheat flour. The wheat-purple rice biscuits contained high fibre contents (4.1%) with small only changes in physical properties. The biscuits also showed positive characteristics using in vitro digestibility methods. The lowest pGI was found in the 100% purple rice flour biscuits. The change in colour of the biscuits was due to the antioxidant compounds from the purple rice flour. The total phenolics, anthocyanin and flavonoid contents of the fortified biscuits ranged from 0.8-3.0 mg gallic acid equivalents/100 g dry weight (DW), anthocyanins 9.4-51.5 mg/kg DW and flavonoids 0.6-1.3 mg catechin equivalents/100 g DW, respectively. Sensory evaluation revealed that panellists liked the 50% substitution level of purple rice flour for wheat flour in the biscuit mix compared to the 75% and 100% substitution levels. The highest crude protein level (11.3%) with the highest protein digestibility (83.5%) was found in the 20% defatted mussel powder biscuits mixed with ginger and galangal compared to biscuits enriched with 10% and 15% defatted mussel powder. The antioxidant compounds and antioxidant activity also significantly increased (P < 0.05), and the total starch contents decreased, when increased amounts of protein from defatted mussel powder were incorporated into the biscuit mix. Overall, the supplementation of 10% defatted mussel powder was accepted by all the ethnic groups with a higher score given than for the 20% supplemented biscuits. Pacific Islanders appreciated the mussel-supplemented biscuits more than the other three ethnic groups, Caucasian, Chinese and Thai. The fortified biscuits enriched with defatted mussel powder and spices contained higher protein (26.4%), fibre (52.9%) and ash (6.0%) contents with a lower fat (5.6%) content compared to the wheat-purple rice biscuits (50:50). The in vitro starch digestibility and pGI decreased in the fortified biscuits by 19% and 6.2%, respectively, while the protein digestibility increased by 3.7%, corresponding to the increased levels of defatted mussel powder present. The inclusion of defatted mussel powder at 15% showed no significant differences in liking scores in terms of colour and overall appearance; whereas, the flavour and overall acceptability scores were significantly lower than the control biscuits from 7.0 to 4.6 and from 7.4 to 5.3, respectively. Storage of the 15% defatted mussel biscuits at 21.6 ± 0.4°C and 34.2 ± 0.1°C in two different packaging types (polyethylene terephthalate, PET and aluminium foil laminate, AL) for 12 weeks showed small reductions in antioxidant compounds and antioxidant activity (P < 0.05), but no changes were observed in the colour and physical parameters. Overall, substitution of purple rice flour can be used as an alternative flour in terms of functional properties to produce a good texture in biscuits with a higher antioxidant potential and lower predicted glycaemic index. Spices can be successfully incorporated into mussel-containing biscuits to improve the overall taste of the biscuits. A combination of lower temperature (21.6 ± 0.4°C) and AL pouches proved to be the best storage condition for biscuits giving, overall, acceptable rates of free fatty acid and peroxide values even after storage for 12 weeks

Effect of Substituting Purple Rice Flour for Wheat Flour on Physicochemical Characteristics, In Vitro Digestibility, and Sensory Evaluation of Biscuits

Purple rice flour contains high levels of a number of antioxidant compounds; however, it has seldom been used as an ingredient in bakery products. The aim was to increase the nutritional value of biscuits by adding purple rice flour to a basic wheat flour biscuit. The substitution of purple rice flour in place of wheat flour modified the characteristics of the biscuits in terms of increasing the nutritional values. They contained high fiber, antioxidants, and antioxidant activities, while slightly changing the physical properties such as hardness and spread ratio. The study showed that the protein digestibility increased as the content of the purple rice flour was increased in the biscuit mix. The 100% purple rice flour biscuits had the lowest predicted glycemic index (pGI) of all the biscuits. Sensory analysis showed that the overall acceptability of the blended flour biscuits at 25 and 50% substitution levels was slightly less than that of the control biscuits with only 9%; however, the scores were above 5 which means the panelists still liked the biscuits a lot. Overall, the inclusion of purple rice flour in biscuits mix increased crude protein content, protein digestibility, and bioactive compounds with acceptable sensory scores from consumers up to 50% substitution of purple rice

Effect on quality characteristics of tomatoes grown under well-watered and drought stress conditions

Tomatoes are one of the most nutritionally and economically important crops in New Zealand and around the world. Tomatoes require large amounts of water to grow well and are adversely affected by drought stress. However, few studies have evaluated the physicochemical characteristics of commercial tomatoes grown under water stress conditions. Four tomato cultivars (Incas, Marmande, Scoresby Dwarf, and Window Box Red) were grown in a greenhouse under well-watered and drought stress conditions and the tomatoes were harvested when ripe. The physicochemical properties and antioxidant contents of the fruits were compared. There were significant differences between cultivars in quality characteristics-such as dry matter, total soluble solids, and pH parameters-but there were no differences in the quality characteristics between the two treatments of the fruits (p > 0.05); however, there were significant differences (p < 0.05) in the antioxidant compositions (lycopene, total phenolics, and flavonoids) and antioxidant activities (DPPH and ABTS) of the fruits of both cultivars and treatments. Overall, these results indicated that tomatoes increased their bioactive compounds without changing any quality characteristics when exposed to water stress conditions

Physicochemical properties and sensory evaluation of wheat-purple rice biscuits enriched with green-lipped mussel powder (Perna canaliculus) and spices

Biscuits are one of the most consumed bakery products eaten by everyone. Purple rice contains much higher levels of antioxidants, vitamins, and minerals such as iron and zinc compared to wheat. The aim of this work was to produce a protein-rich biscuit made from purple rice flour and defatted green-lipped mussel powder (Perna canaliculus) (0-20%) blended with ginger and galangal spices at 4% for each spice. The objective was to produce an inexpensive, balanced, healthy snack product containing increased levels of protein and antioxidants from the mussel powder and to investigate the consumer preferences of these biscuits using the four different ethnic groups (Thai, Chinese, Caucasian, and Pacific Islanders) living in New Zealand. The addition of the mussel powder increased the crude protein content by 43% and the protein digestibility by 21% at the highest level of inclusion. The addition of mussel powder significantly (p<0.05) increased the hardness of biscuits while making small increases in the browning index of the cooked biscuit. The phenolic contents and antioxidant activities (DPPH and ABTS) were significantly (p<0.05) increased as additional amounts of mussel powder were incorporated into the biscuit mix, resulting in a reduction in the total starch contents. The addition of 10% mussel powder to the control biscuit mix was accepted by all the ethnic groups. Overall, the Pacific Islanders showed a higher appreciation for all the attributes tested.Postgraduate Research Fund, Lincoln University, Canterbury, NZ

Effect of Bleaching Processes on Physicochemical and Functional Properties of Cellulose and Carboxymethyl Cellulose from Young and Mature Coconut Coir

The objective of this study was to characterize the properties of cellulose and CMC synthesized from young and mature coconut coir with different bleaching times (bleaching for the first time; 1 BT, bleaching for a second time; 2 BT, and bleaching for the third time; 3 BT) using hydrogen peroxide (H2O2). The surface morphology, structural information, chemical compositions, and crystallinity of both cellulose and CMC were determined. H2O2 bleaching can support delignification by reducing hemicellulose and lignin, as evidenced by FTIR showing a sharp peak at wave number 1260 cm−1. The cellulose and CMC from coconut coir can be more dispersed and have greater functional characteristics with increasing bleaching times due to the change in accessibility of hydroxyl groups in the structure. The CMC diffraction patterns of coconut coir after the bleaching process showed the destruction of the crystalline region of the original cellulose. The SEM images showed that the surface of CMC was smoother than that of cellulose. The CMCy had a higher water holding capacity (WHC) compared to the CMCm as the bleaching can increase interaction between the polymer and water molecules. Therefore, the best quality of CMC corresponds to CMCy. Based on these findings, bleaching time has a strong effect on the functional properties of cellulose and CMC from coconut coir

Mechanical and Physicochemical Properties of Composite Biopolymer Films Based on Carboxymethyl Cellulose from Young Palmyra Palm Fruit Husk and Rice Flour

Carboxymethyl cellulose from young Palmyra palm fruit husk (CMCy) film has low water barrier properties, which can limit its application. Thus, the combination of CMCy with other polysaccharides, such as rice flour (RF), may solve this problem. The aim of this study is to prepare the CMCy/RF composite films in different proportions (CMCy100, CMCy75/RF25, CMCy50/RF50, CMCy25/RF75, and RF100) and investigate their mechanical and physicochemical properties. The film strength (33.36–12.99 MPa) and flexibility (9.81–3.95%) of the CMCy/RF composite films decreased significantly (p −8 g m m−2 s−1 Pa−1) and film solubility (82.70–21.64%) of the CMCy/RF composite films. Furthermore, an increased lightness with a coincidental decreased yellowness of the CMCy/RF composite films was pronounced when the RF proportion increased (p < 0.05). However, the addition of RF in different proportions did not influence the film thickness and transparency. Based on SEM micrographs, all film samples had a relatively coarser surface. FTIR spectra showed that some interactions between CMCy and RF blended films had occurred. According to these findings, the CMCy50/RF50 composite film was found to be the best formulation because it has good mechanical and physicochemical properties

Carboxymethyl Bacterial Cellulose from Nata de Coco: Effects of NaOH

Bacterial cellulose from nata de coco was prepared from the fermentation of coconut juice with Acetobacter xylinum for 10 days at room temperature under sterile conditions. Carboxymethyl cellulose (CMC) was transformed from the bacterial cellulose from the nata de coco by carboxymethylation using different concentrations of sodium hydroxide (NaOH) and monochloroacetic acid (MCA) in an isopropyl (IPA) medium. The effects of various NaOH concentrations on the degree of substitution (DS), chemical structure, viscosity, color, crystallinity, morphology and the thermal properties of carboxymethyl bacterial cellulose powder from nata de coco (CMCn) were evaluated. In the carboxymethylation process, the optimal condition resulted from NaOH amount of 30 g/100 mL, as this provided the highest DS value (0.92). The crystallinity of CMCn declined after synthesis but seemed to be the same in each condition. The mechanical properties (tensile strength and percentage of elongation at break), water vapor permeability (WVP) and morphology of CMCn films obtained from CMCn synthesis using different NaOH concentrations were investigated. The tensile strength of CMCn film synthesized with a NaOH concentration of 30 g/100 mL increased, however it declined when the amount of NaOH concentration was too high. This result correlated with the DS value. The highest percent elongation at break was obtained from CMCn films synthesized with 50 g/100 mL NaOH, whereas the elongation at break decreased when NaOH concentration increased to 60 g/100 mL

Carboxymethyl Bacterial Cellulose from Nata de Coco: Effects of NaOH

Bacterial cellulose from nata de coco was prepared from the fermentation of coconut juice with Acetobacter xylinum for 10 days at room temperature under sterile conditions. Carboxymethyl cellulose (CMC) was transformed from the bacterial cellulose from the nata de coco by carboxymethylation using different concentrations of sodium hydroxide (NaOH) and monochloroacetic acid (MCA) in an isopropyl (IPA) medium. The effects of various NaOH concentrations on the degree of substitution (DS), chemical structure, viscosity, color, crystallinity, morphology and the thermal properties of carboxymethyl bacterial cellulose powder from nata de coco (CMCn) were evaluated. In the carboxymethylation process, the optimal condition resulted from NaOH amount of 30 g/100 mL, as this provided the highest DS value (0.92). The crystallinity of CMCn declined after synthesis but seemed to be the same in each condition. The mechanical properties (tensile strength and percentage of elongation at break), water vapor permeability (WVP) and morphology of CMCn films obtained from CMCn synthesis using different NaOH concentrations were investigated. The tensile strength of CMCn film synthesized with a NaOH concentration of 30 g/100 mL increased, however it declined when the amount of NaOH concentration was too high. This result correlated with the DS value. The highest percent elongation at break was obtained from CMCn films synthesized with 50 g/100 mL NaOH, whereas the elongation at break decreased when NaOH concentration increased to 60 g/100 mL

Synthesis, Characterization, and Application of Carboxymethyl Cellulose from Asparagus Stalk End

Cellulose from Asparagus officinalis stalk end was extracted and synthesized to carboxymethyl cellulose (CMCas) using monochloroacetic acid (MCA) via carboxymethylation reaction with various sodium hydroxide (NaOH) concentrations starting from 20% to 60%. The cellulose and CMCas were characterized by the physical properties, Fourier Transform Infrared spectroscopy (FTIR), Differential scanning calorimetry (DSC), Scanning electron microscopy (SEM) and X-ray diffraction (XRD). In addition, mechanical properties of CMCas films were also investigated. The optimum condition for producing CMCas was found to be 30% of NaOH concentration for the carboxymethylation reaction, which provided the highest percent yield of CMCas at 44.04% with the highest degree of substitution (DS) at 0.98. The melting point of CMCas decreased with increasing NaOH concentrations. Crystallinity of CMCas was significantly deformed (p &lt; 0.05) after synthesis at a high concentration. The L* value of the CMCas was significantly lower at a high NaOH concentration compared to the cellulose. The highest tensile strength (44.59 MPa) was found in CMCas film synthesized with 40% of NaOH concentration and the highest percent elongation at break (24.99%) was obtained in CMCas film treated with 30% of NaOH concentration. The applications of asparagus stalk end are as biomaterials in drug delivery system, tissue engineering, coating, and food packaging

Effect of Monochloroacetic Acid on Properties of Carboxymethyl Bacterial Cellulose Powder and Film from Nata de Coco

Nata de coco has been used as a raw material for food preparation. In this study, the production of carboxymethyl cellulose (CMC) film from nata de coco and the effect of monochloroacetic acid on carboxymethyl bacterial cellulose (CMCn) and its film were investigated. Bacterial cellulose from nata de coco was modified into CMC form via carboxymethylation using various concentrations of monochloroacetic acid (MCA) at 6, 12, 18, and 24 g per 15 g of cellulose. The results showed that different concentrations of MCA affected the degree of substitution (DS), chemical structure, viscosity, color, crystallinity, and morphology of CMCn. The optimum treatment for carboxymethylation was found using 24 g of MCA per 15 g of cellulose, which provided the highest DS at 0.83. The morphology of CMCn was related to DS value; a higher DS value showed denser and smoother surface than nata de coco cellulose. The various MCA concentrations increased the mechanical properties (tensile strength and percentage of elongation at break) and water vapor permeability of CMCn, which were related to the DS value