Evaluation on safety and sensory analysis of xylitol substituted dadih

Dadih is a favourable dessert in South East Asia due to its appealing sweet taste and jellies appearance. The sweet taste is from sugar (sucrose) content, and in order to reduce the sucrose, it was substituted with xylitol. Xylitol can provides intense sweetness with less calories and lower water activity, which potentially contribute to higher microbial stability thus giving longer shelf life. The objective of this study was to evaluate the effect of xylitol substituted on dadih safety and sensory qualities. Dadih was prepared by replacing sucrose with xylitol composition in the range of 0 – 100% and at two levels of cooking times (15 and 20 minutes). Safety analysis were performed using total plate count (TPC) and water activity (aw) analysis. For sensory analysis, seven attributes were evaluated (appearance, colour, hardness, elasticity, taste, sweetness, and overall acceptability) based on the 9-hedonic scale. From the findings, dadih samples with total sucrose (0%) were observed to be contaminated faster compared to total xylitol (100%). Dadih with xylitol is more stable with prolonged shelf life. From sensory analysis, dadih sample prepared with shorter cooking time (15 minutes) was selected as more favourable with overall acceptability score between 72 - 85%. More than 70% of the score for dadih with xylitol substitute was above ‘slightly like’, which indicates a promising future to produce xylitol substitute dadih. The outcome of this study has shown that xylitol is potentially to be utilize as sugar substitute for dadih production

Assessment on rheological and texture properties of xylitol-substituted dadih

Dadih is a dairy-based dessert made of milk, water, sugar and agar, which is popular especially among South East Asian people. It has sweet taste due to high sugar content in its formulation. An excessive intake of sugar is harmful to human health, and it would be beneficial if the conventional sugar is replaced by a sugar substitute. In order to formulate a healthier dadih, xylitol was used to replace sucrose in three different levels of compositions (0, 50 and 100%), which xylitol provides intense sweetness with fewer calories. Therefore, the objective of this study was to evaluate the effect of xylitol substitution on rheological and textural properties of xylitol-substituted dadih. Process parameters were cooking temperatures (85–95C) and cooking times (10–20 min). It was found that cooking temperature had the biggest impact on dadih. All samples showed gel-like behavior where the value of G′ (storage modulus) was higher than G″ (loss modulus). Samples that were prepared under high temperatures illustrated higher value of G′ with elastic gel property regardless of the xylitol composition. Sample prepared at 95C cooking temperature, 20-min cooking time and 0% xylitol exhibited the highest value of hardness and internal gel strength with 0.892 N ± 0.002 and 0.248 N ± 0.006, respectively. In general, the presence of xylitol in dadih contributed to its softer texture compared to a product that is made from sucrose. However, xylitol-substituted dadih prepared at 85C with longer cooking time (15 to 20 min) met the required texture as conventional dadih

Potensi rizom serai Acheh (Elettariopsis smithiae) sebagai punca tumbuhan antioksida : kesan suhu dan masa pengekstrakan terhadap antioksida, perubahan warna dan sebatian meruap

Serai Acheh (Elettariopsis smithiae) ialah tumbuhan herba daripada famili Zingiberaceae (Halia) yang digunakan dalam perawatan tradisi. Matlamat kajian ini adalah untuk mengkaji potensi rizom serai Acheh sebagai punca antioksidan semula jadi, mengenal pasti komponen meruap dan menilai perubahan warna yang disebabkan oleh pengekstrakan pada pelbagai parameter. Sampel dikeringkan dalam ketuhar vakum (45 ℃, 0.4 bar) dan diekstrak dengan air suling pada 1:50 (sampel: pelarut) pada pelbagai suhu (50 ℃, 60 ℃, 70 ℃) dan masa (40 min, 80 min, 120 min). Pengekstrakan pada suhu 60 ºC selama 120 minit mencatatkan TPC tertinggi iaitu sebanyak 84.59 mg GAE/g manakala pengekstrakan pada suhu 60 ºC selama 40 minit merekodkan nilai FRAP tertinggi iaitu 1176.4 μM FeII/g berbanding sampel lain. Sampel yang diekstrak pada suhu 70 ºC selama 80 minit mencatatkan peratus penyingkiran radikal DPPH tertinggi iaitu 83.37%, namun begitu tiada perbezaan yang signifikan (p>0.05) berbanding sampel yang diekstrak pada suhu 60 ºC selama 80 minit. Nilai peratus penyingkiran radikal kation ABTS tertinggi iaitu 69.59% juga dicatatkan pada suhu pengekstrakan 60 ºC selama 80 minit. Pengekstrakan rizom serai Acheh pada suhu 60 ºC selama 80 minit adalah yang paling optimum. Kesan perlakuan suhu dan masa pengekstrakan juga menyumbang kepada perubahan warna (ΔE) ekstrak rizom serai Acheh yang signifikan (p<0.05) terhadap sampel kawalan. Sebatian eukaliptol, fensil alkohol, borneol, fensil asetat dan 4-etinil-4,8,8-trimetil-2-metilidenabisiklo [5.2.0] nonana adalah sebatian meruap yang dominan ditemui pada sampel kawalan dan sampel rizom serai Acheh yang telah diekstrak pada keadaan optimum. Kandungan antioksida dan kehadiran sebatian meruap membuktikan bahawa rizom serai Acheh mempunyai potensi sebagai punca antioksida semula jadi dan menjadi alternatif kepada antioksida sintetik

Sugar recovery from bakery leftovers through enzymatic hydrolysis : effect of process conditions and product characterization

This study evaluates the process conditions, (enzyme concentration (120-1200 U/g substrate), temperature (30-60 °C), and pH (3-9)) of enzymatic hydrolysis (EH) for sugar recovery from leftover croissants (LC) and leftover doughnut (LD), and characterizing its residue and hydrolysate. The highest sugar yield recovered from LC was 574.21 ± 0.74 mg/g (840 U/g substrate, 49 °C and pH 3) and for LD was 460.53 ± 0.74 mg/g (1176 U/g substrate, 47 °C and pH 3). The highest fructose and glucose yield for LC and LD were 14.47±0.73 mg/g and 11.84±0.21 mg/g, and 13.26±0.63 mg/g and 10.34±0.11 mg/g, respectively. Morphology analysis (SEM) showed that the structure of LC and LD had changes in its starch granules that indicates hydrolysis process occurrence. The presence of monosaccharides and oligosaccharides were detected from FTIR. HMF was also detected from sugar degradation due to EH, (0.043 ± 0.0334 mg/g for LC) and (0.023 ± 0.0124 mg/g for LD)

Risk assessment of subcritical water hydrolysis (SWH) system for sugar recovery using failure modes and effects analysis (FMEA) methods

The subcritical water hydrolysis (SWH) process has proven to be an effective method for sugar recovery from bakery waste. However, the natural principle of the process involving high pressure and temperature has made it a hazardous operation. Hence, failure mode and effect analysis (FMEA) has been applied to identify the potential failure modes in subcritical water hydrolysis (SWH) systems. The Risk Priority Number (RPN) approach was used to rate each potential problem during the SWH process. The reactor unit was found to have the highest potential for failure by RPN value of 800 with the ‘failure effect analysis’ on the potential reactor cap to explode due to the very high pressure inside the reactor that developed during SWH. The failure consequences may lead to injury or even death. As a result of the FMEA assessment approach and several corrective action plans, the failure risks of SWH can be reduced and managed effectively

Consumers' delayed consumption of bakery products: effect on physical and chemical properties

Delay in the consumption of bakery products has contributed to the food waste problem, which is a serious global issue. Delayed consumption or can be regarded as the ‘leftovers’ bakery products such as croissants and doughnuts are normally discarded due to the impairment in texture or quality degradation causing them to taste not as good as fresh baked, although the products still edible. Thus, this study aims to evaluate the physical and chemical changes during the delaying of consumption of croissants and doughnuts at three (3) different storage times (day 0, 1 and 2). The hardness of croissants and doughnuts had an increased throughout storage time, with doughnuts have the higher hardness than croissants, with 175.63 % and 92.31 % increased, respectively. Carbohydrate was found as the major component for croissants and doughnuts. Croissants and doughnuts recorded carbohydrate content of (50.32-52.42 %) and (43.22-46.59 %), respectively, from day 0 to day 2. While sugar profile analysis detected three types of monosaccharides sugars, which were fructose, glucose and maltose for croissants and doughnuts. Thus, high content of carbohydrate and monosaccharides that available in the leftovers doughnut and croissants suggest that it could potentially be used as renewable resources for sugar recovery

Hydrolysis and characterization of sugar recovery from bakery waste under optimized subcritical water conditions

Subcritical water hydrolysis process for sugar recovery from leftover croissants (LC) and leftover doughnuts (LD) was optimised using response surface methodology with three process parameters as dependent variables and sugar yield as the response. The process parameters: temperature (160-200 °C), time (5-15 min), and solid loading (10-50%), on the sugar yield were investigated. For the LC sample, the optimised process conditions were determined to be: 200 °C, 6.17 min, and 10% solid loading producing an 80% hydrolysis yield of 466.11 ± 0.67 mg/g. Comparatively, the LD sample optimisation parameters were: 200 °C, 5 min, and 10% solid loading producing a 76.18% hydrolysis yield of 394.34 ± 0.33 mg/g. The sugar extracts were further characterise; which through scanning electron microscopy revealed the LC had most starch granules rupture during hydrolysis, while Fourier-transform infrared spectroscopy detected the presence of monosaccharides and oligosaccharides for both LC and LD. 5-hydroxymethylfurfural (5-HMF), a sugar degradation by-product, was also detected with 39.16 ± 0.61 and 20.59 ± 0.81 mg/g for the LC and LD, respectively, at optimal conditions

Evaluation of rheological properties and quality of xylitol-substituted dadih

Dadih is a dairy based dessert made of milk, water, sugar, and agar that is popular especially among South East Asian people. It has sweet taste due to high sugar content in its formulation. An excessive sugar intake is harmful to human health, and it would be beneficial if conventional sugar is replaced by a sugar substitute. In order to produce a healthier dadih, xylitol that has less energy and possesses sweetening power comparable to sucrose, was used as sugar substitute. To produce a new product such as xylitol substituted dadih, it is crucial to evaluate the suitable range of process parameters with various xylitol compositions in properties and quality. In this study, the evaluated properties were in terms of mechanical (rheological and texture) and thermal properties. Safety (total plate count and water activity) and sensory analysis were measured to evaluate the dadih quality. Thus, the first section of this current research was to investigate the effects of process conditions and xylitol concentrations in term of rheological and textural properties of dadih. Process conditions set up were cooking temperatures (85-95˚C) and cooking times (10-20 minutes) while the xylitol set up were at three levels of compositions (0%, 50%, and 100%). It was found that cooking temperature had the biggest impact on rheological and textural properties of dadih. All dadih samples showed an elastic characteristic (n’<1) with gel-like behavior where value of G’ (storage modulus) was higher than G” (loss modulus). In general, the presence of xylitol in dadih contributed to softer texture compared to product that is made from sucrose. Thus, xylitol substituted dadih prepared at 85C with cooking time 15 and 20 minutes have met the required texture in term of hardness and internal gel strength as the conventional dadih. The second section of this study focused on thermal and safety analysis of dadih prepared at temperature 85˚C with two points of cooking time (15 and 20 minutes). At both cooking time (15 or 20 minutes) as xylitol substitution increase, the onset temperature and enthalpy values were decreased, indicating a weaker structure of dadih with xylitol compared to sucrose. Dadih that was prepared with total xylitol (100%) exhibited the lowest onset temperature To (97.71±0.4˚C for 15 minutes and 99.85±0.18˚C for 20 minutes) and enthalpy values (2096.98±1.4 Jg-1 for 15 minutes and 2422.61±3.6 Jg-1 for 20 minutes). Dadih samples that demonstrated low values of onset temperature and melting enthalpy indicated that less energy was required to change the structure.Safety analysis was done to predict the stability and product quality of xylitol substituted dadih by evaluating microbial growth throughout the storage period of 25 days. From total plate count (TPC) and water activity analysis, all samples was totally spoiled at Day 25 where it contained >300 organism per gram and achieved maximum water activity value, aw (1). Spoilage of dadih with 100% xylitol was slightly prolonged, which was completely spoiled at Day 24 and 25, for 15 and 20 minutes cooking time respectively. However, dadih samples with total sucrose (0%) were observed to be spoiled earlier compared to the former, which was on Day 23. Extended shelf life and stability of dadih substituted xylitol might be due to natural characteristics of xylitol of having low water activity. Last section of this research was to evaluate the sensory analysis of the dadih. Based on eight attributes of sensory analysis, dadih that was prepared at 15 minutes cooking time for both total sucrose (0%) and xylitol (100%) was more preferable compared to samples 20 minutes cooking time. However, there were no significant differences (p > 0.05) for overall acceptability of both samples with 0% and 100% xylitol prepared at 15 minutes cooking time. Based on sensory evaluation, the score for dadih with xylitol substitute was above ‘slight like’, which indicated a promising future to conventionally produce xylitol substitute dadih. Therefore, the outcome of this study has shown that xylitol is potentially to be utilize as sugar substitute for dadih production

Sugar recovery and optimization from bakery leftovers via subcritical water hydrolysis

Subcritical water hydrolysis is an emerging extraction technique that has been acknowledged as a green process. This study aims to recover sugar from leftover croissants (LC) (52.42 ± 0.29% of carbohydrate content) and leftover doughnuts (LD) (46.59 ± 0.23% of carbohydrate content) using subcritical water technique. The first part of this study determines the effect of process parameters (temperature, time and solid loading) of subcritical water hydrolysis (SWH) on sugar recovery. The sugar obtained from leftover samples (LC and LD) increased with an increase in temperature. Contrarily, increasing the solid loading decreased the total sugar yield. Enzymatic hydrolysis (EH), which considered as a conventional process, was also conducted to recover sugar with a different set of process parameters. SWH and EH were optimized using response surface methodology (RSM), where maximum sugar yield was the primary response. SWH recorded the optimised conditions at 200 °C, 6.17 min, and 10% solid loading that producing 466.11 ± 0.67 mg/g for LC, while for LD sample the optimised conditions were found at 200 °C, 5 min, and 10% solid loading with yielded of 394.34 ± 0.33 mg/g. EH recorded the optimum conditions of LC at 0.7% enzyme concentration, 49°C and pH 3 with a sugar yield of 574.21 mg/g, while for LD the optimum process condition was at 0.98% enzyme concentration, 47°C and pH 3 with sugar yield of 460.53 mg/g. The sugar recovered from the optimised process conditions was further characterized in terms of its morphology, chemical composition and its sugar degradation by-products. SEM revealed that starch granules of LC and LD appeared to be more ruptured in the SWH than EH. Meanwhile, FTIR detected the presence of monosaccharides and oligosaccharides from LC and LD hydrolysate. Hydroxymethylfurfural (HMF) was detected higher in SWH than EH. Kinetics of subcritical water hydrolysis were studied, and it was found that SWH was greatly dependent on temperature and time. The findings of this research can be beneficial to the food and pharmaceutical industries. This research can also benefit environmental and energy sustainability areas as it involved a green method in managing food waste issues worldwide

Process development of 'dadih' preparation using xylitol as substitute sugar: effect on thermal and texture characteristics

‘Dadih’ is one of the popular Malaysian puddings and a trad itional food normally consumed as a dessert. Producing healthy ‘dadih’by replacing sugar (sucrose) content with xylitol will provide intense sweetness with fewer calories. The objectives of the present study are to determine the suitable range of process conditions on ‘dadih’ preparation and to investigate the effect of xylitol as substitute sugar on thermal and texture characteristics of ‘ dadih’ samples. This study focuses on second phase or cooking stage. In ‘dadih’ preparation, the compositions of substituted xylitol are varied from 0%, 50% and 100%. The effects of two process parameters were studied and\ud they are cooking temperature (85, 90 and 95 oC) and cooking time (10, 15 and 20 minutes). It was found that the composition of sugar substitute and process parameters were highly affected the thermal and texture characteristics of ‘dadih’. The suitable process conditions to produce ‘dadih’ comparatively with commercial texture characteristics were selected at cooking time between 10 to 20 minutes and cooking temperature at 85°C to 90°C