Estimation of glycaemic index of peach palm (Bactris gasipaes) cooked fruits and chips, and pitahaya (Hylocereus spp.) pulp

The glycaemic index (GI) is a physiological measure of a food’s potential to increase postprandial blood glucose, as compared to the effect produced by food taken as reference, such as glucose or white bread. Currently researchers and consumers are interested in low GI foods, since their consumption is associated with better weight control and reduced risk of incidence of chronic diseases, like diabetes. In the present study, the GI value for peach palm cooked fruit, peach palm chips and pitahaya pulp was estimated. The methodology established by the FAO / WHO for determining the GI of food was used. A total of 12 healthy, non-smoking volunteers were selected and they ingested the fore mentioned foods on different occasions, in 25 g portions of available carbohydrates, after 12-14h overnight fast. Blood glucose levels were measured in 30 min intervals up to 120 min after ingestion. Average GI value was 48 ± 11 for the pitahaya pulp and 35 ± 6 for the peach palm cooked fruit, which may be classified as low glyceamic index foods. The GI of peach palm chips was 60 ± 7, corresponding to a food with a moderate GI. The processing for producing the chips caused an increase in the GI value when compared to the cooked fruit, probably because the stages of milling, moulding and baking promote availability of starch during hydrolysis by the digestive enzymes

Estimación del índice glicémico del fruto cocido y de chips de pejibaye (Bactris gasipaes) y de la pulpa de pitahaya (Hylocereus spp.)

The glycaemic index (GI) is a physiological measure of a food’s potential to increase postprandial blood glucose, as compared to the effect produced by food taken as reference, such as glucose or white bread. Currently researchers and consumers are interested in low GI foods, since their consumption is associated with better weight control and reduced risk of incidence of chronic diseases, like diabetes. In the present study, the GI value for peach palm cooked fruit, peach palm chips and pitahaya pulp was estimated. The methodology established by the FAO / WHO for determining the GI of food was used. A total of 12 healthy, non-smoking volunteers were selected and they ingested the fore mentioned foods on different occasions, in 25 g portions of avai- lable carbohydrates, after 12-14h overnight fast. Blood glucose levels were measured in 30 min inter- vals up to 120 min after ingestion. Average GI value was 48 ± 11 for the pitahaya pulp and 35 ± 6 for the peach palm cooked fruit, which may be classified as low glyceamic index foods. The GI of peach palm chips was 60 ± 7, corresponding to a food with a mo- derate GI. The processing for producing the chips caused an increase in the GI value when compared to the cooked fruit, probably because the stages of mi- lling, moulding and baking promote availability of starch during hydrolysis by the digestive enzymes.El índice glicémico (GI) es una medida fisiológica del potencial de un alimento para incrementar la glucosa sanguínea, en comparación con el efecto producido por un alimento de referencia, tal como la glucosa o el pan blanco. Los investigadores y consumidores tienen interés en los alimentos de bajo GI, dado que su consumo está asociado con un mejor control del peso corporal y una reducción del riesgo de enfermedades crónicas como la diabetes. En el presente estudio se determinó el valor de GI del fruto cocido de pejibaye, de los chips horneados de pejibaye y de la pulpa de pitahaya. Se seleccionaron 12 voluntarios, aparentemente sanos, no fumadores, los cuales consumieron los alimentos evaluados y el alimento de referencia (pan blanco), en una porción que contuviera 25 g de carbohidratos disponibles, después de un período de ayuno de 12-14 h. Los niveles de glucosa en sangre fueron medidos en intervalos de 30 min hasta 120 min después de la ingesta. Se obtuvo un valor promedio de GI de 48 ± 11 para la pitahaya y de 35 ± 6 para el pejibaye cocido, los cuales pueden ser clasificados como alimentos de bajo índice glicémico. El valor de GI de los chips de pejibaye fue de 60 ± 7, lo que corresponde a un alimento de GI moderado. Se encontró que el procesamiento para la obtención de los chips produjo un aumento en el valor del GI, en comparación con el obtenido para la fruta cocida, probablemente debido a que las etapas de molienda, moldeo y horneo favorecen la disponibilidad del almidón para su hidrólisis por parte de las enzimas digestivasUniversidad de Costa Rica/[422-A7-049]/UCR/Costa RicaUCR::Vicerrectoría de Docencia::Salud::Facultad de Medicina::Escuela de MedicinaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Centro Nacional de Ciencia y Tecnología de Alimentos (CITA

التركیب الكاروتیني ، نشاط مضادات الاكسدة ومؤشر نسبة سكر الدم لصنفین من نبات Bactris gasipaes

Peach palm (Bactris gasipaes) is an orange, red or yellow fruit widely cultivated in Central America. It is an energy-rich source of carbohydrates, fats and carotenes, and contains small amounts of protein and fiber. The aim of this study was to describe its carotenoid concentration, antioxidant activity and glycemic index. For the carotenoid composition, antioxidant activity and lipid peroxidation protection two B. gasipaes varieties were analyzed: Ecuador and Yurimaguas. Total carotenoids content was 7.43±0.2 mg/100g for Ecuador and 5.74±0.05 mg/100g for Yurimaguas. The amount of each variety necessary to reach 50% radical scavenging activity (DPPH) was 11.6±0.2mg carotenoids/mL for Yurimaguas and 9.1±0.3mg carotenoids/mL for Ecuador. In addition, the IC50 of the inhibition lipid peroxidation was 11.2±2.1μg carotenoids/ml and 10.9±2.2μg carotenoids/ml for Yurimaguas and Ecuador respectively. Glycemic index value obtained was 35±6, which classified B. gasipaes as a low GI food. It is concluded that peach palm is an important source of carotenoids and its antioxidant activity and low glycemic index can provide nutritional benefits that may play an important role in the prevention or management of several chronic diseases.الملخص !ثمار نخلة الخوخ (gasipaes Bactris (ھي ثمار برتقالیة ، حمراء او صفراء اللون ، تزرع بشكل واسع في عدة مناطق من أمریكا الوسطى. تعد ھذه الثمار من الثمار ذات المحتوى الغني بمصادر الطاقة لاحتوائھا على كربوھیدرات ودھون بالإضافة الى الكاروتینات ، كما تحوي على نسب قلیلة من البروتین والالیاف. والھدف من ھذه الدراسة ھو التعرف على محتوى ھذه الثمار من الكاروتینات ومضادات الاكسدة بالإضافة الى معرف قیمة مؤشر نسبة السكر في الدم. تم اختیار صنفین من نبات نخلة الخوخ ھما Ecuador و Yurimaguas لدراسة محتوى ھذه الثمار من الكاروتینات ومضادات الاكسدة وامكانیة منع تأكسد الدھون. حسب النتائج التي تم التحصل علیھا فقد كان محتوى الكارویتنات الكلیة حوالي ˼˽٫˻ ± ̀٫ ˹ملغ/ ˹˹˺ غرام للصنف Ecuador وحوالي ˽̀٫˹˾ ± ˾٫ ˹ملغ/ ˹˹˺ غرام للصنف Yurimaguas .كما اوضحت الدراسة ان الكمیة اللازمة من كل صنف لرفع نسبة الفعالیة الكاسحة للجذور (DPPH (إلى ˹˾% كانت ˿٫˻ ± ˺˺٫ ˹ملغ كاروتین/مل للصنف Yurimaguas و ˺٩٫˼ ± ٫ ˹ملغ كاروتین/مل للصنف Ecuador .كما أن النصف تركیز المثبطة القصوى (IC50 ( لمثبطات تأكسد الدھون قد بلغت ˻٫˺ ± ˺˺٫ ˻مایكرو غرام كاروتین/مل و ٫٩˻ ± ˺˹٫ ˻مایكرو غرام كاروتین/مل للصنفین Yurimaguas و Ecuador على التوالي. وحسب نتائج قیمة مؤشر نسبة سكر الدم والتي تم الحصول علیھا في ھذه الدراسة وھي ˾˼ ± ˿ ، یمكن تصنیف ثمار نخلة الخوخ من ضمن الاغذیة ذات مؤشر السكر المنخفض. خلصت ھذه الدراسة إلى أھمیة ثمار نخلة الخوخ كمصدر مھم للكاروتینات ومضادات الاكسدة بالإضافة الى كونھا من ضمن الأغذیة ذات مؤشر السكر المنخفض مما یزید من فوائدھا من الناحیة الغذائیة ویزید من الدور المھم الذي یمكن ان تلعبھ للوقایة او السیطرة على العدید من الامراض المزمنةUniversidad de Costa Rica/[422-A5-065]/UCR/Costa RicaUCR::Vicerrectoría de Docencia::Ciencias Agroalimentarias::Facultad de Ciencias Agroalimentarias::Escuela de Tecnología de Alimento

Quillaja saponin variants with central glycosidic linkage modifications exhibit distinct conformations and adjuvant activities

Immunological adjuvants such as the saponin natural product QS-21 help stimulate the immune response to co-administered antigens and have become increasingly important in the development of prophylactic and therapeutic vaccines. However, clinical use of QS-21 is encumbered by chemical instability, dose-limiting toxicity, and low-yielding purification from the natural source. Previous studies of structure-activity relationships in the four structural domains of QS-21 have led to simplified, chemically stable variants that retain potent adjuvant activity and low toxicity in mouse vaccination models. However, modification of the central glycosyl ester linkage has not yet been explored. Herein, we describe the design, synthesis, immunologic evaluation, and molecular dynamics analysis of a series of novel QS-21 variants with different linker lengths, stereochemistry, and flexibility to investigate the role of this linkage in saponin adjuvant activity and conformation. Despite relatively conservative structural modifications, these variants exhibit striking differences in in vivo adjuvant activity that correlate with specific conformational preferences. These results highlight the junction of the triterpene and linear oligosaccharide domains as playing a critical role in the immunoadjuvant activity of the Quillaja saponins and also suggest a mechanism of action involving interaction with a discrete macromolecular target, in contrast to the non-specific mechanisms of emulsion-based adjuvants. © The Royal Society of Chemistry 2016

Molecular Structure, Biosynthesis, and Distribution of Coenzyme Q

Coenzyme Q is a very old molecule in evolutionary terms that has accumulated numerous functions in the cellular metabolism beyond its primordial function, the electron transport. In all organisms, coenzyme Q maintains a highly conserved structure allowing a localization inside cell membranes in a hydrophobic environment thanks to having an isoprenoid tail, and at the same time allows the polar ring benzene to interact with acceptors and electron donors. Coenzyme Q deficiency constitutes a group of mitochondrial diseases. Affected patients suffer mainly a decrease in energy production that induces dysfunctions in most organs and body systems. Current therapeutic alternatives are based on increasing coenzyme Q levels either through induction of endogenous mechanisms or exogenous supplementation. This chapter includes both aspects, the mechanisms associated with the coenzyme Q supplementation and the regulatory mechanisms of coenzyme Q biosynthesis. In terms of synthesis, the structure of coenzyme Q is complicated since it requires the participation of two well-differentiated pathways that must be carefully regulated. The synthesis is carried out through the participation of a multienzyme complex located in the inner mitochondrial membrane and controlled by different levels of regulation that at this time are not well-known